1
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Shao H, Ma ZH, Cheng YY, Guo XF, Sun YK, Liu WJ, Zhao YM. Bioinspired Total Synthesis of Cephalotaxus Diterpenoids and Their Structural Analogues. Angew Chem Int Ed Engl 2024; 63:e202402931. [PMID: 38527934 DOI: 10.1002/anie.202402931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 03/25/2024] [Accepted: 03/25/2024] [Indexed: 03/27/2024]
Abstract
Herein, we present a unified chemical synthesis of three subgroups of cephalotaxus diterpenoids. Key to the success lies in adopting a synthetic strategy that is inspired by biosynthesis but is opposite in nature. By employing selective one-carbon introduction and ring expansion operations, we have successfully converted cephalotane-type C18 dinorditerpenoids (using cephanolide B as a starting material) into troponoid-type C19 norditerpenoids and intact cephalotane-type C20 diterpenoids. This synthetic approach has enabled us to synthesize cephinoid H, 13-oxo-cephinoid H, 7-oxo-cephinoid H, fortalpinoid C, 7-epi-fortalpinoid C, cephanolide E, and 13-epi-cephanolide E. Furthermore, through the development of an intermolecular asymmetric Michael reaction between β-oxo esters and β-substituted enones, we have achieved the enantioselective synthesis of advanced intermediates within our synthetic sequence, thus formally realizing the asymmetric total synthesis of the cephalotaxus diterpenoids family.
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Affiliation(s)
- Hui Shao
- Key Laboratory of Applied Surface and Colloid Chemistry & School of Chemistry and Chemical Engineering, Shaanxi Normal University, 620 West Chang'an Ave, Xi'an, 710119, China
| | - Zhi-Hua Ma
- Key Laboratory of Applied Surface and Colloid Chemistry & School of Chemistry and Chemical Engineering, Shaanxi Normal University, 620 West Chang'an Ave, Xi'an, 710119, China
| | - Yang-Yang Cheng
- Key Laboratory of Applied Surface and Colloid Chemistry & School of Chemistry and Chemical Engineering, Shaanxi Normal University, 620 West Chang'an Ave, Xi'an, 710119, China
| | - Xiao-Feng Guo
- Key Laboratory of Applied Surface and Colloid Chemistry & School of Chemistry and Chemical Engineering, Shaanxi Normal University, 620 West Chang'an Ave, Xi'an, 710119, China
| | - Ya-Kui Sun
- Key Laboratory of Applied Surface and Colloid Chemistry & School of Chemistry and Chemical Engineering, Shaanxi Normal University, 620 West Chang'an Ave, Xi'an, 710119, China
| | - Wen-Jie Liu
- Key Laboratory of Applied Surface and Colloid Chemistry & School of Chemistry and Chemical Engineering, Shaanxi Normal University, 620 West Chang'an Ave, Xi'an, 710119, China
| | - Yu-Ming Zhao
- Key Laboratory of Applied Surface and Colloid Chemistry & School of Chemistry and Chemical Engineering, Shaanxi Normal University, 620 West Chang'an Ave, Xi'an, 710119, China
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2
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Ruyet L, Roblick C, Häfliger J, Wang ZX, Stoffels TJ, Daniliuc CG, Gilmour R. Catalytic Ring Expanding Difluorination: An Enantioselective Platform to Access β,β-Difluorinated Carbocycles. Angew Chem Int Ed Engl 2024; 63:e202403957. [PMID: 38482736 DOI: 10.1002/anie.202403957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Indexed: 04/11/2024]
Abstract
Cyclic β,β-difluoro-carbonyl compounds have a venerable history as drug discovery leads, but limitations in the synthesis arsenal continue to impede chemical space exploration. This challenge is particularly acute in the arena of fluorinated medium rings where installing the difluoromethylene unit subtly alters the ring conformation by expanding the internal angle (∠C-CF2-C>∠C-CH2-C): this provides a handle to modulate physicochemistry (e.g. pKa). To reconcile this disparity, a highly modular ring expansion has been devised that leverages simple α,β-unsaturated esters and amides, and processes them to one-carbon homologated rings with concomitant geminal difluorination (6 to 10 membered rings, up to 95 % yield). This process is a rare example of the formal difluorination of an internal alkene and is enabled by sequential I(III)-enabled O-activation. Validation of enantioselective catalysis in the generation of unprecedented medium ring scaffolds is reported (up to 93 : 7 e.r.) together with X-ray structural analyses and product derivatization.
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Affiliation(s)
- Louise Ruyet
- University of Münster, Institute for Organic Chemistry, Corrensstraße 36, 48149, Münster, Germany
| | - Christoph Roblick
- University of Münster, Institute for Organic Chemistry, Corrensstraße 36, 48149, Münster, Germany
| | - Joel Häfliger
- University of Münster, Institute for Organic Chemistry, Corrensstraße 36, 48149, Münster, Germany
| | - Zi-Xuan Wang
- University of Münster, Institute for Organic Chemistry, Corrensstraße 36, 48149, Münster, Germany
| | - Tobias Jürgen Stoffels
- University of Münster, Institute for Organic Chemistry, Corrensstraße 36, 48149, Münster, Germany
| | - Constantin G Daniliuc
- University of Münster, Institute for Organic Chemistry, Corrensstraße 36, 48149, Münster, Germany
| | - Ryan Gilmour
- University of Münster, Institute for Organic Chemistry, Corrensstraße 36, 48149, Münster, Germany
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3
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Li X, Xu Z. Skeletal Editing: Ring Insertion for Direct Access to Heterocycles. Molecules 2024; 29:1920. [PMID: 38731412 PMCID: PMC11085720 DOI: 10.3390/molecules29091920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2024] [Revised: 04/19/2024] [Accepted: 04/22/2024] [Indexed: 05/13/2024] Open
Abstract
Skeleton editing has rapidly advanced as a synthetic methodology in recent years, significantly streamlining the synthesis process and gaining widespread acceptance in drug synthesis and development. This field encompasses diverse ring reactions, many of which exhibit immense potential in skeleton editing, facilitating the generation of novel ring skeletons. Notably, reactions that involve the cleavage of two distinct rings followed by the reformation of new rings through ring insertion play a pivotal role in the construction of novel ring skeletons. This article aims to compile and systematize this category of reactions, emphasizing the two primary reaction types and offering a thorough exploration of their associated complexities and challenges. Our endeavor is to furnish readers with comprehensive reaction strategies, igniting research interest and injecting fresh impetus into the advancement of this domain.
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Affiliation(s)
| | - Zhigang Xu
- College of Pharmacy, National & Local Joint Engineering Research Center of Targeted and Innovative Therapeutics, IATTI, Chongqing University of Arts and Sciences, Chongqing 402160, China;
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4
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Liu M, Yan N, Tian H, Li B, Zhao D. Ring Expansion toward Disila-carbocycles via Highly Selective C-Si/C-Si Bond Cross-Exchange. Angew Chem Int Ed Engl 2024; 63:e202319187. [PMID: 38388782 DOI: 10.1002/anie.202319187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 02/21/2024] [Accepted: 02/22/2024] [Indexed: 02/24/2024]
Abstract
Herein, we successfully inhibited the preferential homodimerization and C-Si/Si-H bond cross-exchange of benzosilacyclobutenes and monohydro-silacyclobutanes and achieved the first highly selective C-Si/C-Si bond cross-exchange reaction by deliberately tuning the Ni-catalytic system, which constitutes a powerful and atom-economical ring expansion method for preparing medium-sized cyclic compounds bearing two silicon atoms at the ring junction, which are otherwise inaccessible. The DFT calculation explicitly elucidated the pivotal role of Si-H bond at silacyclobutanes and the high ring strain of two substrates in realizing the two C-Si bonds cleavage and reformation in the catalytic cycle.
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Affiliation(s)
- Min Liu
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Nuo Yan
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Haowen Tian
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Bo Li
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Dongbing Zhao
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, China
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5
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Mallick RK, Žabka M, Clayden J. Benzo-fused Nitrogen Heterocycles by Asymmetric Ring Expansion and Stereochemically Retentive Re-contraction of Cyclic Ureas. Angew Chem Int Ed Engl 2024; 63:e202318417. [PMID: 38261257 DOI: 10.1002/anie.202318417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 01/12/2024] [Accepted: 01/22/2024] [Indexed: 01/24/2024]
Abstract
Benzo-fused nitrogen heterocycles are common features of bioactive molecules, and the enantioselective synthesis of their substituted analogues is an important goal. In this paper we demonstrate a practical and mechanistically intriguing approach to the enantioselective synthesis of 1-arylbenzazepines and their analogues. The reaction sequence starts with an asymmetric migratory ring expansion of indoline, tetrahydroquinoline, or tetrahydrobenzazepine ureas on treatment with a chiral lithium amide base. Treatment of the ring-expanded ureas with acid triggers a two-atom ring contraction-an 'azatropic shift' in which one urea nitrogen displaces the other-with almost complete retention of stereochemistry. Aminolysis of the urea products provides enantioenriched 1-aryl-tetrahydrobenzazepine derivatives and their congeners, including an analogue of an intermediate in the synthesis of the drug solifenacin. Deuteration, in situ IR, and DFT studies provide evidence for the mechanisms of the reaction steps.
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Affiliation(s)
- Rajendra K Mallick
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Matej Žabka
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Jonathan Clayden
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
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6
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Ning Y, Chen H, Ning Y, Zhang J, Bi X. Rhodium-Catalyzed One-Carbon Ring Expansion of Aziridines with Vinyl-N-triftosylhydrazones for the Synthesis of 2-Vinyl Azetidines. Angew Chem Int Ed Engl 2024; 63:e202318072. [PMID: 38282137 DOI: 10.1002/anie.202318072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 12/25/2023] [Accepted: 01/26/2024] [Indexed: 01/30/2024]
Abstract
Azetidines, being four-membered N-heterocycles, possess significant potential in contemporary medicinal chemistry owing to their favorable pharmacokinetic properties. Regrettably, the incorporation of functionalized azetidines into pharmaceutical lead structures has been impeded by the absence of efficient synthetic methods for their synthesis. In this study, a Rh-catalyzed one-carbon ring expansion of aziridines with vinyl-N-triftosylhydrazones is presented, which facilitates the synthesis of high value-added 2-alkenyl azetidine products. This research represents the first example of ring expansion of aziridines enabled by vinyl carbenes. Additionally, a one-pot two-step protocol, initiated from cinnamaldehyde, was successfully achieved, offering a step-economical and facile approach for the synthesis of these compounds. The pivotal aspect of this successful transformation lies in the in situ formation of an alkenyl aziridinium ylide intermediate. Experimental investigations, coupled with computational studies, suggest that a diradical pathway is involved in the reaction mechanism.
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Affiliation(s)
- Yongquan Ning
- Department of Chemistry, Northeast Normal University, 130024, Changchun, China
| | - Hongzhu Chen
- Department of Chemistry, Northeast Normal University, 130024, Changchun, China
| | - Yongyue Ning
- Department of Chemistry, Northeast Normal University, 130024, Changchun, China
| | - Jin Zhang
- Department of Chemistry, Northeast Normal University, 130024, Changchun, China
| | - Xihe Bi
- Department of Chemistry, Northeast Normal University, 130024, Changchun, China
- State Key Laboratory of Elemento-Organic Chemistry, Nankai University, 300071, Tianjin, China
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7
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Tsuda M, Morita T, Morita Y, Takaya J, Nakamura H. Methylene Insertion into Nitrogen-Heteroatom Single Bonds of 1,2-Azoles via a Zinc Carbenoid: An Alternative Tool for Skeletal Editing. Adv Sci (Weinh) 2024; 11:e2307563. [PMID: 38148471 PMCID: PMC10933618 DOI: 10.1002/advs.202307563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 12/10/2023] [Indexed: 12/28/2023]
Abstract
The nitrogen-heteroatom single bonds of 1,2-azoles and isoxazolines underwent methylene insertion in the presence of CH2 I2 (6 equiv.) and diethylzinc (3 equiv.) to produce a wide variety of the ring-expanded six-membered heterocycles. Density functional theory calculations suggest that the methylene insertion proceeds via cleavage of nitrogen-heteroatom single bonds followed by ring closure.
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Affiliation(s)
- Masato Tsuda
- School of Life Science and TechnologyTokyo Institute of Technology4259 Nagatsuta‐cho Midori‐kuYokohama226–8501Japan
| | - Taiki Morita
- School of Life Science and TechnologyTokyo Institute of Technology4259 Nagatsuta‐cho Midori‐kuYokohama226–8501Japan
- Laboratory for Chemistry and Life ScienceInstitute of Innovative ResearchTokyo Institute of Technology4259 Nagatsuta‐cho Midori‐kuYokohama226–8501Japan
| | - Yuto Morita
- Department of ChemistrySchool of ScienceTokyo Institute of TechnologyO‐okayamaMeguro‐kuTokyo152–8551Japan
| | - Jun Takaya
- Department of ChemistrySchool of ScienceTokyo Institute of TechnologyO‐okayamaMeguro‐kuTokyo152–8551Japan
| | - Hiroyuki Nakamura
- School of Life Science and TechnologyTokyo Institute of Technology4259 Nagatsuta‐cho Midori‐kuYokohama226–8501Japan
- Laboratory for Chemistry and Life ScienceInstitute of Innovative ResearchTokyo Institute of Technology4259 Nagatsuta‐cho Midori‐kuYokohama226–8501Japan
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8
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Orukotan WE, Palate KY, Pogrányi B, Bobinski P, Epton RG, Duff L, Whitwood AC, Grogan G, Lynam JM, Unsworth WP. Divergent Cascade Ring-Expansion Reactions of Acryloyl Imides. Chemistry 2024; 30:e202303270. [PMID: 37987097 DOI: 10.1002/chem.202303270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 11/16/2023] [Accepted: 11/21/2023] [Indexed: 11/22/2023]
Abstract
Macrocyclic and medium-sized ring ketones, lactones and lactams can all be made from common acryloyl imide starting materials through divergent, one-pot cascade ring-expansion reactions. Following either conjugate addition with an amine or nitromethane, or osmium(VIII)-catalysed dihydoxylation, rearrangement through a four-atom ring expansion takes place spontaneously to form the ring expanded products. A second ring expansion can also be performed following a second iteration of imide formation and alkene functionalisation/ring expansion. In the dihydroxylation series, three- or four-atom ring expansion can be performed selectively, depending on whether the reaction is under kinetic or thermodynamic control.
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Affiliation(s)
- Will E Orukotan
- Department of Chemistry, University of York, York, YO10 5DD, UK
| | | | - Balázs Pogrányi
- Department of Chemistry, University of York, York, YO10 5DD, UK
| | - Philipp Bobinski
- Organisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Ryan G Epton
- Department of Chemistry, University of York, York, YO10 5DD, UK
| | - Lee Duff
- Department of Chemistry, University of York, York, YO10 5DD, UK
| | | | - Gideon Grogan
- Department of Chemistry, University of York, York, YO10 5DD, UK
| | - Jason M Lynam
- Department of Chemistry, University of York, York, YO10 5DD, UK
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9
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Todd M, Hrdina R. Synthesis of 1,2-Disubstituted Adamantane Derivatives by Construction of the Adamantane Framework. Molecules 2023; 28:7636. [PMID: 38005358 PMCID: PMC10675813 DOI: 10.3390/molecules28227636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 11/14/2023] [Accepted: 11/15/2023] [Indexed: 11/26/2023] Open
Abstract
This review summarizes achievements in the synthesis of 1,2-disubstituted adamantane derivatives by the construction of the tricyclic framework either by total synthesis or by ring expansion/contraction reactions of corresponding adamantane homologues. It is intended to complement reviews focusing on the preparation of 1,2-disubstituted derivatives by C-H functionalization methods.
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Affiliation(s)
| | - Radim Hrdina
- Department of Organic Chemistry, Faculty of Science, Charles University, Hlavova 8, 12043 Praha, Czech Republic;
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10
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Dhak MS, Arunprasath D, Argent SP, Cuthbertson JD. A Domino Radical Amidation/Semipinacol Approach to All-Carbon Quaternary Centers Bearing an Aminomethyl Group. Chemistry 2023; 29:e202300922. [PMID: 37278542 PMCID: PMC10947466 DOI: 10.1002/chem.202300922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 06/01/2023] [Accepted: 06/02/2023] [Indexed: 06/07/2023]
Abstract
A photoredox-mediated radical amidation ring-expansion sequence that enables the generation of all-carbon quaternary centers bearing a protected aminomethyl substituent is described. The methodology can be applied to both styrene and unactivated alkene substrates generating structurally diverse sp3 -rich amine derivatives in a concise manner.
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Affiliation(s)
- Mandeep S. Dhak
- GlaxoSmithKline Carbon Neutral Laboratories for Sustainable ChemistryUniversity of Nottingham, Jubilee CampusTriumph RoadNottinghamNG7 2TUUK
- School of ChemistryUniversity of NottinghamUniversity ParkNottinghamNG7 2RDUK
| | - Dhanarajan Arunprasath
- GlaxoSmithKline Carbon Neutral Laboratories for Sustainable ChemistryUniversity of Nottingham, Jubilee CampusTriumph RoadNottinghamNG7 2TUUK
- School of ChemistryUniversity of NottinghamUniversity ParkNottinghamNG7 2RDUK
| | - Stephen P. Argent
- School of ChemistryUniversity of NottinghamUniversity ParkNottinghamNG7 2RDUK
| | - James D. Cuthbertson
- GlaxoSmithKline Carbon Neutral Laboratories for Sustainable ChemistryUniversity of Nottingham, Jubilee CampusTriumph RoadNottinghamNG7 2TUUK
- School of ChemistryUniversity of NottinghamUniversity ParkNottinghamNG7 2RDUK
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11
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Vinogradov DB, Izmest’ev AN, Kravchenko AN, Strelenko YA, Gazieva GA. Synthesis of imidazo[4,5- e][1,3]thiazino[2,3- c][1,2,4]triazines via a base-induced rearrangement of functionalized imidazo[4,5- e]thiazolo[2,3- c][1,2,4]triazines. Beilstein J Org Chem 2023; 19:1047-1054. [PMID: 37533878 PMCID: PMC10390826 DOI: 10.3762/bjoc.19.80] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 07/11/2023] [Indexed: 08/04/2023] Open
Abstract
A series of imidazo[4,5-e][1,3]thiazino[2,3-c][1,2,4]triazines was synthesized via a cascade sequence of hydrolysis and skeletal rearrangement of imidazo[4,5-e]thiazolo[2,3-c][1,2,4]triazin-7(8H)-ylidene)acetic acid esters in methanol upon treatment with excess KOH. Imidazo[4,5-e]thiazolo[3,2-b][1,2,4]triazin-6(7H)-ylidene)acetic acid esters are also suitable substrates for the reaction. In this case hydrolysis and thiazole ring expansion were accompanied with the change of the thiazolotriazine junction type from thiazolo[3,2-b][1,2,4]triazine to thiazino[2,3-c][1,2,4]triazine.
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Affiliation(s)
- Dmitry B Vinogradov
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky Prosp., Moscow 119991, Russian Federation
| | - Alexei N Izmest’ev
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky Prosp., Moscow 119991, Russian Federation
| | - Angelina N Kravchenko
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky Prosp., Moscow 119991, Russian Federation
| | - Yuri A Strelenko
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky Prosp., Moscow 119991, Russian Federation
| | - Galina A Gazieva
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky Prosp., Moscow 119991, Russian Federation
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12
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Joynson BW, Cumming GR, Ball LT. Photochemically Mediated Ring Expansion of Indoles and Pyrroles with Chlorodiazirines: Synthetic Methodology and Thermal Hazard Assessment. Angew Chem Int Ed Engl 2023:e202305081. [PMID: 37294032 DOI: 10.1002/anie.202305081] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 06/08/2023] [Accepted: 06/09/2023] [Indexed: 06/10/2023]
Abstract
We demonstrate that arylchlorodiazirines serve as photo-activated halocarbene precursors for the selective one-carbon ring expansion of N-substituted pyrroles and indoles to the corresponding pyridinium and quinolinium salts. Preliminary investigations indicate that the same strategy also enables the conversion of N-substituted pyrazoles to pyrimidinium salts. The N-substituent of the substrate plays an essential role in: (1) increasing substrate scope by preventing product degradation, (2) enhancing yields by suppressing co-product inhibition, and (3) activating the azinium products towards subsequent synthetic manipulations. This latter point is illustrated by subjecting the quinolinium salts to four complementary partial reductions, which provide concise access to ring-expanded products with different degrees of increased C(sp3) character. Thermal analysis of the diazirines by differential scanning calorimetry (DSC) provides detailed insight into their energetic properties, and highlights the safety benefits of photolyzing - rather than thermolyzing - these reagents.
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Affiliation(s)
| | - Graham R Cumming
- Eli Lilly and Company, Discovery Chemistry Research & Technology, SPAIN
| | - Liam Thomas Ball
- University of Nottingham, School of Chemistry, The University of Nottingham, University Park, NG7 2RD, Nottingham, UNITED KINGDOM
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13
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Yin ZC, Li M, Niu C, Wang WF, Liu WR, Zhang QW, Wang GW. Simultaneous Ring Contraction and Expansion Reaction: Electrosynthesis of Heterocycle-Fused Fulleroids and Photovoltaic Application. Angew Chem Int Ed Engl 2023:e202304321. [PMID: 37099448 DOI: 10.1002/anie.202304321] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 04/25/2023] [Accepted: 04/26/2023] [Indexed: 04/27/2023]
Abstract
Simultaneous electrochemical ring contraction and expansion reactions remain unexplored to date. Herein, the reductive electrosynthesis of heterocycle-fused fulleroids from fullerotetrahydropyridazines and electrophiles in the presence of a trace amount of oxygen has been achieved with concurrent ring contraction and ring expansion. When trifluoroacetic acid and alkyl bromides are employed as electrophiles, heterocycle-fused fulleroids with a 1,1,2,6-configuration are regioselectively formed. In contrast, heterocycle-fused fulleroids with a 1,1,4,6-configuration are regioselectively produced as two separable stereoisomers if phthaloyl chloride is used as the electrophile. The reaction proceeds through multiple steps of electroreduction, heterocycle ring-opening, oxygen oxidation, heterocycle contraction, fullerene cage expansion, and nucleophilic addition. The structures of these fulleroids have been determined by spectroscopic data and single-crystal X-ray diffraction analyses. The observed high regioselectivities have been rationalized by theoretical calculations. Representative fulleroids have been applied in organic solar cells as the third component and exhibit good performance.
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Affiliation(s)
- Zheng-Chun Yin
- University of Science and Technology of China, Department of Chemistry, 96 Jinzhai Road, 230026, Hefei, CHINA
| | - Mingjie Li
- University of Science and Technology of China, Department of Chemistry, CHINA
| | - Chuang Niu
- University of Science and Technology of China, Department of Chemistry, CHINA
| | - Wei-Feng Wang
- University of Science and Technology of China, Department of Chemistry, CHINA
| | - Wen-Rui Liu
- University of Science and Technology of China, Department of Chemistry, CHINA
| | - Qian-Wen Zhang
- University of Science and Technology of China, Department of Chemistry, CHINA
| | - Guan-Wu Wang
- University of Science and Technology of China, Department of Chemistry, 96 Jinzhai Road, 230026, Hefei, CHINA
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14
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Bischof T, Beßler L, Krummenacher I, Erhard L, Braunschweig H, Finze M. Construction of a Diverse Range of Boron Heterocycles via Ring Expansion of a Carboranyl-Substituted 9-Borafluorene. Chemistry 2023; 29:e202300210. [PMID: 36794763 DOI: 10.1002/chem.202300210] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 02/09/2023] [Accepted: 02/15/2023] [Indexed: 02/17/2023]
Abstract
Direct insertion of unsaturated substrates into a five-membered borole ring is a useful method to obtain valuable heterocycles containing one or more three-coordinate boron atoms. A 9-o-carboranyl-9-borafluorene, in which the o-carboranyl substituent is connected via one of the cluster carbon atoms to the boron atom of the 9-borafluorene unit, was found to react with a vast array of unsaturated molecules, such as alkynes, aldehydes and various organic azides, to form larger boraheterocyclic products. The ring expansion reactions of the central borole ring proceed rapidly at room temperature, cementing the role of the o-carboranyl substituent in enhancing the insertion reactivity of 9-borafluorenes.
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Affiliation(s)
- Tobias Bischof
- Julius-Maximilians-Universität Würzburg: Julius-Maximilians-Universitat Wurzburg, Inorganic Chemistry, GERMANY
| | - Lukas Beßler
- Julius-Maximilians-Universität Würzburg: Julius-Maximilians-Universitat Wurzburg, Inorganic Chemistry, GERMANY
| | - Ivo Krummenacher
- Julius-Maximilians-Universität Würzburg: Julius-Maximilians-Universitat Wurzburg, Inorganic Chemistry, GERMANY
| | - Leon Erhard
- Julius-Maximilians-Universität Würzburg: Julius-Maximilians-Universitat Wurzburg, Inorganic Chemistry, GERMANY
| | - Holger Braunschweig
- Julius-Maximilians-Universität Würzburg: Julius-Maximilians-Universitat Wurzburg, Inorganic Chemistry, GERMANY
| | - Maik Finze
- Julius-Maximilians-Universitaet Wuerzburg, Institut fuer Anorganische Chemie, Am Hubland, 97074, Wuerzburg, GERMANY
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15
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Wang J, Li J, Zhao C. A Lewis Acid-Promoted Michael Addition and Ring-Expansion Cascade for the Construction of Nitrogen-Containing Medium-Sized Rings. Molecules 2023; 28. [PMID: 36838638 DOI: 10.3390/molecules28041650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 02/03/2023] [Accepted: 02/04/2023] [Indexed: 02/11/2023] Open
Abstract
A Lewis acid-promoted annulation of azadienes and cyclobutamines was developed. This reaction proceeded through Michael addition and ring-expansion cascade, affording the corresponding nitrogen-containing medium-sized rings with a broad scope in moderate to high yields. The catalytic asymmetric version of this reaction has also been explored using a chiral base.
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16
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Schumacher C, Fritz L, Hanek LM, Sidorin V, Brüx D, Bolm C. Reshuffle Bonds by Ball Milling: A Mechanochemical Protocol for Charge-Accelerated Aza-Claisen Rearrangements. Molecules 2023; 28. [PMID: 36677865 DOI: 10.3390/molecules28020807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 01/02/2023] [Accepted: 01/07/2023] [Indexed: 01/15/2023] Open
Abstract
This study presents the development of a mechanochemical protocol for a charge-accelerated aza-Claisen rearrangement. The protocol waives the use of commonly applied transition metals, ligands, or pyrophoric Lewis acids, e.g., AlMe3. Based on (heterocyclic) tertiary allylamines and acyl chlorides, the desired tertiary amides were prepared in yields ranging from 17% to 84%. Moreover, the same protocol was applied for a Belluš-Claisen-type rearrangement resulting in the synthesis of a 9-membered lactam without further optimization.
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17
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Leverenz M, Masson G, Pardo DG, Cossy J. Synthesis of Azocanes from Piperidines via an Azetidinium Intermediate. Chemistry 2021; 27:16325-16328. [PMID: 34643301 DOI: 10.1002/chem.202102739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Indexed: 11/11/2022]
Abstract
α-Trifluoromethyl azocanes are accessible from 2-(trifluoropropan-2-ol) piperidines by metal-free ring-expansion involving a bicyclic azetidinium intermediate. The opening of the azetidinium intermediate was achieved by various nucleophiles (amines, alcoholates, carboxylates, phosphonates, halides and pseudo-halides) with an excellent regio- diastereo- and enantioselectivity and in good yields. The relative configuration of the piperidines and azocanes were assigned and the deprotected azocanes offer opportunities for further derivatization.
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Affiliation(s)
- Malte Leverenz
- Molecular, Macromolecular Chemistry and Materials, UMR 7167 ESPCI Paris, CNRS, PSL University, 10 rue Vauquelin, 75231, Paris Cedex 05, France
| | - Guillaume Masson
- Molecular, Macromolecular Chemistry and Materials, UMR 7167 ESPCI Paris, CNRS, PSL University, 10 rue Vauquelin, 75231, Paris Cedex 05, France
| | - Domingo Gomez Pardo
- Molecular, Macromolecular Chemistry and Materials, UMR 7167 ESPCI Paris, CNRS, PSL University, 10 rue Vauquelin, 75231, Paris Cedex 05, France
| | - Janine Cossy
- Molecular, Macromolecular Chemistry and Materials, UMR 7167 ESPCI Paris, CNRS, PSL University, 10 rue Vauquelin, 75231, Paris Cedex 05, France
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18
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Sosič I, Gobec M, Steinebach C, Schlesinger M, Bendas G, Gütschow M. Another structural correction for 1-oxo-1H-phenalene-2,3-dicarbonitriles: Synthesis of a potent BCL-2 inhibiting 7-phenoxy derivative. Arch Pharm (Weinheim) 2021; 354:e2100151. [PMID: 34173255 DOI: 10.1002/ardp.202100151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 06/03/2021] [Accepted: 06/07/2021] [Indexed: 11/12/2022]
Abstract
Aromatic scaffolds are an important part of biologically active compounds and molecular probes used to study biochemical pathways and the involved targeted proteins of interest. 1-Oxo-1H-phenalene-2,3-dicarbonitrile-based compounds have been described as inhibitors of the BCL-2 family of proteins, and this core structure represents numerous possibilities for modifications that could lead to improved inhibitory potencies. Many studies demonstrated intriguing characteristics of these compounds in terms of reactivity and, interestingly, some contradictory literature reports appeared about reaction outcomes to synthesize them. Here, we initially provide a condensed overview of transformations performed on the phenalene scaffold, followed by the resynthesis of a 6-phenoxy-substituted derivative. We show that the initial determination of this particular structure was wrong and provide two-dimensional nuclear magnetic resonance (NMR) evidence to assign the structure properly. When preparing new derivatives using the same synthetic route, we observed 6- and 7-substituted regioisomers. After confirming their structures by NMR experiments, the ability of these compounds to inhibit BCL-2 was evaluated. The most potent 1-oxo-1H-phenalene-2,3-dicarbonitrile derivatives inhibited BCL-2 in the nanomolar range and showed double-digit micromolar cytotoxicity against four different cancer cell lines.
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Affiliation(s)
- Izidor Sosič
- Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
| | - Martina Gobec
- Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
| | - Christian Steinebach
- Department of Pharmaceutical & Medicinal Chemistry, Pharmaceutical Institute, University of Bonn, Bonn, Germany
| | - Martin Schlesinger
- Department of Pharmaceutical & Cell Biological Chemistry, Pharmaceutical Institute, University of Bonn, Bonn, Germany
| | - Gerd Bendas
- Department of Pharmaceutical & Cell Biological Chemistry, Pharmaceutical Institute, University of Bonn, Bonn, Germany
| | - Michael Gütschow
- Department of Pharmaceutical & Medicinal Chemistry, Pharmaceutical Institute, University of Bonn, Bonn, Germany
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19
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Piesch M, Reichl S, Seidl M, Balázs G, Scheer M. Synthesis and Multiple Subsequent Reactivity of Anionic cyclo-E 3 Ligand Complexes (E=P, As). Angew Chem Int Ed Engl 2021; 60:15101-15108. [PMID: 33961722 PMCID: PMC8251822 DOI: 10.1002/anie.202103683] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Indexed: 12/14/2022]
Abstract
A synthetic pathway for the synthesis of novel anionic sandwich complexes with a cyclo-E3 (E=P, As) ligand as an end deck was developed giving [Cp'''Co(η3 -E3 )]- (Cp'''=1,2,4-tri-tert-butylcyclopentadienyl, E=P ([5]), As ([6])) in good yields suitable for further reactivity studies. In the reaction with the chlorophosphanes R2 PCl (R=Ph, Cy, t Bu), neutral complexes with a disubstituted cyclo-E3 P (E=P, As) ligand in [Cp'''Co(η3 -E3 PR2 )] (E=P (7 a-c), As (9 a-c)) were obtained. These compounds can be partially or completely converted into complexes with a cyclo-E3 (E=P, As) ligand with an exocyclic {PR2 } unit in [Cp'''Co(η2 :η1 -E3 PR2 )] (E=P (8 a-c), As (10 a-c)). Additionally, the insertion of the chlorosilylene [LSiCl] (L=(t BuN)2 CPh) into the cyclo-E3 ligand of [5] and [6] was achieved and the novel heteroatomic complexes [Cp'''Co(η3 -E3 SiL)] (E=P (11), As (12)) could be isolated. The reaction pathway was elucidated by DFT calculations.
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Affiliation(s)
- Martin Piesch
- Institut für Anorganische ChemieUniversität Regensburg93040RegensburgGermany
| | - Stephan Reichl
- Institut für Anorganische ChemieUniversität Regensburg93040RegensburgGermany
| | - Michael Seidl
- Institut für Anorganische ChemieUniversität Regensburg93040RegensburgGermany
| | - Gábor Balázs
- Institut für Anorganische ChemieUniversität Regensburg93040RegensburgGermany
| | - Manfred Scheer
- Institut für Anorganische ChemieUniversität Regensburg93040RegensburgGermany
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20
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Neufeld J, Stünkel T, Mück-Lichtenfeld C, Daniliuc CG, Gilmour R. Trifluorinated Tetralins via I(I)/I(III)-Catalysed Ring Expansion: Programming Conformation by [CH 2 CH 2 ] → [CF 2 CHF] Isosterism. Angew Chem Int Ed Engl 2021; 60:13647-13651. [PMID: 33721384 PMCID: PMC8251640 DOI: 10.1002/anie.202102222] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 03/12/2021] [Indexed: 12/15/2022]
Abstract
Saturated, fluorinated carbocycles are emerging as important modules for contemporary drug discovery. To expand the current portfolio, the synthesis of novel trifluorinated tetralins has been achieved. Fluorinated methyleneindanes serve as convenient precursors and undergo efficient difluorinative ring expansion with in situ generated p‐TolIF2 (>20 examples, up to >95 %). A range of diverse substituents are tolerated under standard catalysis conditions and this is interrogated by Hammett analysis. X‐ray analysis indicates a preference for the CH−F bond to occupy a pseudo‐axial orientation, consistent with stabilising σC−H→σC−F* interactions. The replacement of the symmetric [CH2−CH2] motif by [CF2−CHF] removes the conformational degeneracy intrinsic to the parent tetralin scaffold leading to a predictable half‐chair. The conformational behavior of this novel structural balance has been investigated by computational analysis and is consistent with stereoelectronic theory.
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Affiliation(s)
- Jessica Neufeld
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 36, 48149, Münster, Germany
| | - Timo Stünkel
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 36, 48149, Münster, Germany
| | - Christian Mück-Lichtenfeld
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 36, 48149, Münster, Germany
| | - Constantin G Daniliuc
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 36, 48149, Münster, Germany
| | - Ryan Gilmour
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 36, 48149, Münster, Germany
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21
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Abstract
The reduction of the 1‐phospha‐2‐azanorbornene derivate endo‐1 with lithium aluminium hydride leads to an unprecedented 1‐phosphabicyclo[3.2.1]octa‐2,5‐diene, while a phospholide anion is formed with lithium. The latter can be protonated resulting in formation of an unusual 2H‐phosphole dimer. Furthermore, 3H‐phospholes, previously assumed to have no synthetic relevance as intermediates, were proposed to act as dienophile in the dimerisation of 3,4‐dimethyl‐1‐phenylphosphole at elevated temperatures based on theoretical calculations.
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Affiliation(s)
- Peter Wonneberger
- Leipzig University, Faculty of Chemistry and Mineralogy, Institute of Inorganic Chemistry, Johannisallee 29, 04103, Leipzig, Germany
| | - Nils König
- Leipzig University, Faculty of Chemistry and Mineralogy, Institute of Inorganic Chemistry, Johannisallee 29, 04103, Leipzig, Germany
| | - Menyhárt B Sárosi
- Leipzig University, Faculty of Chemistry and Mineralogy, Institute of Inorganic Chemistry, Johannisallee 29, 04103, Leipzig, Germany
| | - Evamarie Hey-Hawkins
- Leipzig University, Faculty of Chemistry and Mineralogy, Institute of Inorganic Chemistry, Johannisallee 29, 04103, Leipzig, Germany
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22
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Jäger C, Bruneau C, Wagner PK, Prechtl MHG, Deska J. Methanol-Driven Oxidative Rearrangement of Biogenic Furans - Enzyme Cascades vs. Photobiocatalysis. Front Chem 2021; 9:635883. [PMID: 33898389 PMCID: PMC8058437 DOI: 10.3389/fchem.2021.635883] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 01/08/2021] [Indexed: 11/24/2022] Open
Abstract
The oxidative ring expansion of bio-derived furfuryl alcohols to densely functionalized six-membered O-heterocycles represents an attractive strategy in the growing network of valorization routes to synthetic building blocks out of the lignocellulosic biorefinery feed. In this study, two scenarios for the biocatalytic Achmatowicz-type rearrangement using methanol as terminal sacrificial reagent have been evaluated, comparing multienzymatic cascade designs with a photo-bio-coupled activation pathway.
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Affiliation(s)
| | - Cloé Bruneau
- Department of Chemistry, Aalto University, Espoo, Finland
| | | | - Martin H. G. Prechtl
- Department of Chemistry, University of Cologne, Cologne, Germany
- Instituto Superior Técnico, University of Lisbon, Lisboa, Portugal
| | - Jan Deska
- Department of Chemistry, Aalto University, Espoo, Finland
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23
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Gregson CHU, Noble A, Aggarwal VK. Divergent, Strain-Release Reactions of Azabicyclo[1.1.0]butyl Carbinols: Semipinacol or Spiroepoxy Azetidine Formation. Angew Chem Int Ed Engl 2021; 60:7360-7365. [PMID: 33555105 PMCID: PMC8247891 DOI: 10.1002/anie.202100583] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Indexed: 12/17/2022]
Abstract
The azetidine moiety is a privileged motif in medicinal chemistry and new methods that access them efficiently are highly sought after. Towards this goal, we have found that azabicyclo[1.1.0]butyl carbinols, readily obtained from the highly strained azabicyclo[1.1.0]butane (ABB), can undergo divergent strain-release reactions upon N-activation. Treatment with trifluoroacetic anhydride or triflic anhydride triggered a semipinacol rearrangement to give keto 1,3,3-substituted azetidines. More than 20 examples were explored, enabling us to evaluate selectivity and the migratory aptitude of different groups. Alternatively, treatment of the same alcohols with benzyl chloroformate in the presence of NaI led to iodohydrin intermediates which gave spiroepoxy azetidines upon treatment with base. The electronic nature of the activating agent dictates which pathway operates.
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Affiliation(s)
| | - Adam Noble
- School of ChemistryUniversity of BristolCantock's CloseBristolBS8 1TSUK
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24
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Shabalin DA, Ivanova EE, Ushakov IA, Schmidt EY, Trofimov BA. Hydrazides in the reaction with hydroxypyrrolines: less nucleophilicity - more diversity. Beilstein J Org Chem 2021; 17:319-324. [PMID: 33564339 PMCID: PMC7849252 DOI: 10.3762/bjoc.17.29] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 01/21/2021] [Indexed: 11/23/2022] Open
Abstract
Expedient protocols for the synthesis of three types of highly functionalized azaheterocyclic scaffolds (dihydropyridazines, tetrahydropyridazines, and partially saturated tricyclic systems) from readily available hydroxypyrrolines and hydrazides are described. The directions of the transformation of a common initial intermediate, namely a Brønsted acid-activated hydroxypyrroline, depend on the reaction conditions and the structure of the hydrazides.
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Affiliation(s)
- Dmitrii A Shabalin
- A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, 1 Favorsky St, 664033 Irkutsk, Russian Federation
| | - Evgeniya E Ivanova
- A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, 1 Favorsky St, 664033 Irkutsk, Russian Federation
| | - Igor A Ushakov
- A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, 1 Favorsky St, 664033 Irkutsk, Russian Federation
| | - Elena Yu Schmidt
- A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, 1 Favorsky St, 664033 Irkutsk, Russian Federation
| | - Boris A Trofimov
- A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, 1 Favorsky St, 664033 Irkutsk, Russian Federation
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25
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Shang J, Thombare VJ, Charron CL, Wille U, Hutton CA. Ring Expansion of Thiolactams via Imide Intermediates: An Amino Acid Insertion Strategy. Chemistry 2021; 27:1620-1625. [PMID: 33289186 DOI: 10.1002/chem.202005035] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Indexed: 12/22/2022]
Abstract
The AgI -promoted reaction of thiolactams with N-Boc amino acids yields an N-(α-aminoacyl) lactam that can rearrange through an acyl transfer process. Boc-deprotection results in convergence to the ring-expanded adduct, thereby facilitating an overall insertion of an amino acid into the thioamide bond to generate medium-sized heterocycles. Application to the site-specific insertion of amino acids into cyclic peptides is demonstrated.
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Affiliation(s)
- Jing Shang
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Vic 3010, Australia
| | - Varsha J Thombare
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Vic 3010, Australia
| | - Carlie L Charron
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Vic 3010, Australia
| | - Uta Wille
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Vic 3010, Australia
| | - Craig A Hutton
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Vic 3010, Australia
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26
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Du J, Yang X, Wang X, An Q, He X, Pan H, Zuo Z. Photocatalytic Aerobic Oxidative Ring Expansion of Cyclic Ketones to Macrolactones by Cerium and Cyanoanthracene Catalysis. Angew Chem Int Ed Engl 2021; 60:5370-5376. [PMID: 33259085 DOI: 10.1002/anie.202012720] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 11/16/2020] [Indexed: 12/17/2022]
Abstract
We describe a cerium-catalyzed aerobic oxidative ring expansion for the expedient construction of synthetically challenging macrolactones under visible-light conditions. Cyanoanthracene has been employed as co-catalyst to accelerate the turnover of the cerium cycle leading to a fast conversion within 20 min of irradiation. Taking advantage of the high efficiency and operationally simple conditions, a collection of over 100 macrolactones equipped with ring systems ranging from 9- to 19-membered macrocycles have been prepared from simple building blocks. Moreover, the enabling potential of this strategy to simplify the generation of molecular complexity has been demonstrated through the concise synthesis of sonnerlactone.
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Affiliation(s)
- Jianbo Du
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China.,University of Chinese Academy of Science, Beijing, 100049, China
| | - Xiaokun Yang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China.,University of Chinese Academy of Science, Beijing, 100049, China
| | - Xin Wang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China.,University of Chinese Academy of Science, Beijing, 100049, China
| | - Qing An
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China.,University of Chinese Academy of Science, Beijing, 100049, China
| | - Xu He
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China.,University of Chinese Academy of Science, Beijing, 100049, China
| | - Hui Pan
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China.,University of Chinese Academy of Science, Beijing, 100049, China
| | - Zhiwei Zuo
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 200032, China
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27
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Lei X, Li Y, Lai Y, Hu S, Qi C, Wang G, Tang Y. Strain-Driven Dyotropic Rearrangement: A Unified Ring-Expansion Approach to α-Methylene-γ-butyrolactones. Angew Chem Int Ed Engl 2020; 60:4221-4230. [PMID: 33155345 DOI: 10.1002/anie.202013169] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Indexed: 12/16/2022]
Abstract
An unprecedented strain-driven dyotropic rearrangement of α-methylene-β-lactones has been realized, which enables the efficient access of a wide range of α-methylene-γ-butyrolactones displaying remarkable structural diversity. Several appealing features of the reaction, including excellent efficiency, high stereospecificity, predictable chemoselectivity and broad substrate scope, render it a powerful tool for the synthesis of MBL-containing molecules of either natural or synthetic origin. Both experimental and computational evidences suggest that the new variant of dyotropic rearrangements proceed in a dualistic pattern: while an asynchronous concerted mechanism most likely accounts for the reactions featuring hydrogen migration, a stepwise process involving a phenonium ion intermediate is favored in the cases of aryl migration. The great synthetic potential of the title reaction is exemplified by its application to the efficient construction of several natural products and relevant scaffolds.
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Affiliation(s)
- Xiaoqiang Lei
- School of Pharmaceutical Sciences, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing, 100084, China
| | - Yuanhe Li
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education and Beijing National Laboratory for Molecular Science (BNLMS), College of Chemistry, Peking University, Beijing, 100871, China
| | - Yang Lai
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education and Beijing National Laboratory for Molecular Science (BNLMS), College of Chemistry, Peking University, Beijing, 100871, China
| | - Shengkun Hu
- School of Pharmaceutical Sciences, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing, 100084, China
| | - Chen Qi
- School of Pharmaceutical Sciences, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing, 100084, China
| | - Gelin Wang
- School of Pharmaceutical Sciences, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing, 100084, China
| | - Yefeng Tang
- School of Pharmaceutical Sciences, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing, 100084, China
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28
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Riesinger C, Dütsch L, Balázs G, Bodensteiner M, Scheer M. Cationic Functionalisation by Phosphenium Ion Insertion. Chemistry 2020; 26:17165-17170. [PMID: 32996637 PMCID: PMC7839539 DOI: 10.1002/chem.202003291] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 09/21/2020] [Indexed: 12/12/2022]
Abstract
The reaction of [Cp'''Ni(η3 -P3 )] (1) with in situ generated phosphenium ions [RR'P]+ yields the unprecedented polyphosphorus cations of the type [Cp'''Ni(η3 -P4 R2 )][X] (R=Ph (2 a), Mes (2 b), Cy (2 c), 2,2'-biphen (2 d), Me (2 e); [X]- =[OTf]- , [SbF6 ]- , [GaCl4 ]- , [BArF ]- , [TEF]- ) and [Cp'''Ni(η3 -P4 RCl)][TEF] (R=Ph (2 f), tBu (2 g)). In the reaction of 1 with [Br2 P]+ , an analogous compound is observed only as an intermediate and the final product is an unexpected dinuclear complex [{Cp'''Ni}2 (μ,η3 :η1 :η1 -P4 Br3 )][TEF] (3 a). A similar product [{Cp'''Ni}2 (μ,η3 :η1 :η1 -P4 (2,2'-biphen)Cl)][GaCl4 ] (3 b) is obtained, when 2 d[GaCl4 ] is kept in solution for prolonged times. Although the central structural motif of 2 a-g consists of a "butterfly-like" folded P4 ring attached to a {Cp'''Ni} fragment, the structures of 3 a and 3 b exhibit a unique asymmetrically substituted and distorted P4 chain stabilised by two {Cp'''Ni} fragments. Additional DFT calculations shed light on the reaction pathway for the formation of 2 a-2 g and the bonding situation in 3 a.
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Affiliation(s)
- Christoph Riesinger
- Institute of Inorganic ChemistryUniversity of Regensburg93040RegensburgGermany
| | - Luis Dütsch
- Institute of Inorganic ChemistryUniversity of Regensburg93040RegensburgGermany
| | - Gábor Balázs
- Institute of Inorganic ChemistryUniversity of Regensburg93040RegensburgGermany
| | | | - Manfred Scheer
- Institute of Inorganic ChemistryUniversity of Regensburg93040RegensburgGermany
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29
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Lawer A, Epton RG, Stephens TC, Palate KY, Lodi M, Marotte E, Lamb KJ, Sangha JK, Lynam JM, Unsworth WP. Evaluating the Viability of Successive Ring-Expansions Based on Amino Acid and Hydroxyacid Side-Chain Insertion. Chemistry 2020; 26:12674-12683. [PMID: 32432817 PMCID: PMC7589337 DOI: 10.1002/chem.202002164] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Indexed: 01/20/2023]
Abstract
The outcome of ring-expansion reactions based on amino/hydroxyacid side-chain insertion is strongly dependent on ring size. This manuscript, which builds upon our previous work on Successive Ring Expansion (SuRE) methods, details efforts to better define the scope and limitations of these reactions on lactam and β-ketoester ring systems with respect to ring size and additional functionality. The synthetic results provide clear guidelines as to which substrate classes are more likely to be successful and are supported by computational results, using a density functional theory (DFT) approach. Calculating the relative Gibbs free energies of the three isomeric species that are formed reversibly during ring expansion enables the viability of new synthetic reactions to be correctly predicted in most cases. The new synthetic and computational results are expected to support the design of new lactam- and β-ketoester-based ring-expansion reactions.
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Affiliation(s)
- Aggie Lawer
- Department of ChemistryUniversity of YorkYorkYO10 5DDUK
| | - Ryan G. Epton
- Department of ChemistryUniversity of YorkYorkYO10 5DDUK
| | | | | | - Mahendar Lodi
- Department of ChemistryUniversity of YorkYorkYO10 5DDUK
| | - Emilie Marotte
- ENSICAEN6 Boulevard Maréchal Juin, CS 4505314050Caen Cedex 04France
| | - Katie J. Lamb
- Department of ChemistryUniversity of YorkYorkYO10 5DDUK
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30
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Tymann DC, Benedix L, Iovkova L, Pallach R, Henke S, Tymann D, Hiersemann M. Photochemical Approach to the Cyclohepta[b]indole Scaffold by Annulative Two-Carbon Ring-Expansion. Chemistry 2020; 26:11974-11978. [PMID: 32463529 PMCID: PMC7540574 DOI: 10.1002/chem.202002581] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Indexed: 12/12/2022]
Abstract
We report on the implementation of the concept of a photochemically elicited two-carbon homologation of a π-donor-π-acceptor substituted chromophore by triple-bond insertion. Implementing a phenyl connector between the slide-in module and the chromophore enabled the synthesis of cylohepta[b]indole-type building blocks by a metal-free annulative one-pot two-carbon ring expansion of the five-membered chromophore. Post-irradiative structural elaboration provided founding members of the indolo[2,3-d]tropone family of compounds. Control experiments in combination with computational chemistry on this multibond reorganization process founded the basis for a mechanistic hypothesis.
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Affiliation(s)
| | - Lars Benedix
- Fakultät für Chemie und Chemische BiologieTU Dortmund44227DortmundGermany
| | - Lyuba Iovkova
- Fakultät für Chemie und Chemische BiologieTU Dortmund44227DortmundGermany
| | - Roman Pallach
- Fakultät für Chemie und Chemische BiologieTU Dortmund44227DortmundGermany
| | - Sebastian Henke
- Fakultät für Chemie und Chemische BiologieTU Dortmund44227DortmundGermany
| | - David Tymann
- Fakultät für Chemie und Chemische BiologieTU Dortmund44227DortmundGermany
| | - Martin Hiersemann
- Fakultät für Chemie und Chemische BiologieTU Dortmund44227DortmundGermany
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31
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Abstract
Harnessing the chemistry of onium ylide intermediates generated from transition metal catalysis is a powerful strategy to convert simple precursors into complex scaffolds. While the chemistry of onium ylides has been studied for over three decades, transformations of aziridinium ylides have just recently emerged as a versatile way to exploit the strain of these reactive intermediates to furnish densely functionalized N-heterocycles in a highly stereocontrolled manner. Herein, we provide a short overview of the key concepts and recent developments in this area, with a focus on how mechanistic studies to delineate the factors controlling the reactivity of aziridinium ylides can stimulate fruitful future investigations.
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Affiliation(s)
- Hillary J Dequina
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Jennifer M Schomaker
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
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32
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Abstract
Thietanes are important aliphatic four-membered thiaheterocycles that are found in the pharmaceutical core and structural motifs of some biological compounds. They are also useful intermediates in organic synthesis. Various synthetic methods of thietanes have been developed, including inter- and intramolecular nucleophilic thioetherifications, photochemical [2 + 2] cycloadditions, ring expansions and contractions, nucleophilic cyclizations, and some miscellaneous methods. The recently developed methods provide some new strategies for the efficient preparation of thietanes and their derivatives. This review focuses on the synthetic methods to construct thietane backbones developed during 1966 to 2019.
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Affiliation(s)
- Jiaxi Xu
- State Key Laboratory of Chemical Resource Engineering, Department of Organic Chemistry, College of Chemistry, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China
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33
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He T, Wang G, Bonetti V, Klare HFT, Oestreich M. Silylium-Ion-Promoted (5+1) Cycloaddition of Aryl-Substituted Vinylcyclopropanes and Hydrosilanes Involving Aryl Migration. Angew Chem Int Ed Engl 2020; 59:12186-12191. [PMID: 32302454 PMCID: PMC7383577 DOI: 10.1002/anie.202004320] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 04/17/2020] [Indexed: 11/09/2022]
Abstract
A transition‐metal‐free (5+1) cycloaddition of aryl‐substituted vinylcyclopropanes (VCPs) and hydrosilanes to afford silacyclohexanes is reported. Catalytic amounts of the trityl cation initiate the reaction by hydride abstraction from the hydrosilane, and further progress of the reaction is maintained by self‐regeneration of the silylium ions. The new reaction involves a [1,2] migration of an aryl group, eventually furnishing 4‐ rather than 3‐aryl‐substituted silacyclohexane derivatives as major products. Various control experiments and quantum‐chemical calculations support a mechanistic picture where a silylium ion intramolecularly stabilized by a cyclopropane ring can either undergo a kinetically favored concerted [1,2] aryl migration/ring expansion or engage in a cyclopropane‐to‐cyclopropane rearrangement.
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Affiliation(s)
- Tao He
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
| | - Guoqiang Wang
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
| | - Vittorio Bonetti
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
| | - Hendrik F T Klare
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
| | - Martin Oestreich
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
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34
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Lambert KM, Cox JB, Liu L, Jackson AC, Yruegas S, Wiberg KB, Wood JL. Total Synthesis of (±)-Phyllantidine: Development and Mechanistic Evaluation of a Ring Expansion for Installation of Embedded Nitrogen-Oxygen Bonds. Angew Chem Int Ed Engl 2020; 59:9757-9766. [PMID: 32271982 DOI: 10.1002/anie.202003829] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 04/05/2020] [Indexed: 11/06/2022]
Abstract
The development of a concise total synthesis of (±)-phyllantidine (1), a member of the securinega family of alkaloids containing an unusual oxazabicyclo[3.3.1]nonane core, is described. The synthesis employs a unique synthetic strategy featuring the ring expansion of a substituted cyclopentanone to a cyclic hydroxamic acid as a key step that allows facile installation of the embedded nitrogen-oxygen (N-O) bond. The optimization of this sequence to effect the desired regiochemical outcome and its mechanistic underpinnings were assessed both computationally and experimentally. This synthetic approach also features an early-stage diastereoselective aldol reaction to assemble the substituted cyclopentanone, a mild reduction of an amide intermediate without N-O bond cleavage, and the rapid assembly of the butenolide found in (1) via use of the Bestmann ylide.
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Affiliation(s)
- Kyle M Lambert
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place 97348, Waco, TX, 76798, USA
| | - Joshua B Cox
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place 97348, Waco, TX, 76798, USA
| | - Lin Liu
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place 97348, Waco, TX, 76798, USA
| | - Amy C Jackson
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place 97348, Waco, TX, 76798, USA
| | - Sam Yruegas
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place 97348, Waco, TX, 76798, USA
| | - Kenneth B Wiberg
- Department of Chemistry, Yale University, New Haven, CT, 06520, USA.,865 Central Avenue, Needham, MA, 02492, USA
| | - John L Wood
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place 97348, Waco, TX, 76798, USA
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35
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Strehl J, Kahrs C, Müller T, Hilt G, Christoffers J. Electrochemical-Induced Ring Transformation of Cyclic α-(ortho-Iodophenyl)-β-oxoesters. Chemistry 2020; 26:3222-3225. [PMID: 31850604 PMCID: PMC7155071 DOI: 10.1002/chem.201905570] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Indexed: 01/09/2023]
Abstract
Cyclic α-(ortho-iodophenyl)-β-oxoesters were converted in a ring-expanding transformation to furnish benzannulated cycloalkanone carboxylic esters. The reaction sequence started by electrochemical reduction of the iodoarene moiety. In a mechanistic rationale, the resulting carbanionic species was adding to the carbonyl group under formation of a strained, tricyclic benzocyclobutene intermediate, which underwent carbon-carbon bond cleavage and rearrangement of the carbon skeleton by retro-aldol reaction. The scope of the reaction sequence was investigated by converting cyclic oxoesters with different ring sizes yielding benzocycloheptanone, -nonanone and -decanone derivatives in moderate to good yields. Furthermore, acyclic starting materials and cyclic compounds carrying additional substituents on the iodophenyl ring were submitted to this reaction sequence. The starting materials for this transformation are straightforwardly obtained by conversion of β-oxoesters with phenyliodobis(trifluoroacetate).
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Affiliation(s)
- Julia Strehl
- Institut für ChemieCarl von Ossietzky Universität Oldenburg26111OldenburgGermany
| | - Christoph Kahrs
- Institut für ChemieCarl von Ossietzky Universität Oldenburg26111OldenburgGermany
| | - Thomas Müller
- Institut für ChemieCarl von Ossietzky Universität Oldenburg26111OldenburgGermany
| | - Gerhard Hilt
- Institut für ChemieCarl von Ossietzky Universität Oldenburg26111OldenburgGermany
| | - Jens Christoffers
- Institut für ChemieCarl von Ossietzky Universität Oldenburg26111OldenburgGermany
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36
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Abstract
Several bis(dimethylamino)-substituted 1,4-diaza-2,3-diborinines (DADBs) were synthesized with variable substituents at the backbone nitrogen atoms. By reaction with HCl or BX3 (X=Br, I), these species were successfully converted into their synthetically more useful halide congeners. The high versatility of the generated B-X bonds in further functionalization reactions at the boron centers was demonstrated by means of salt elimination (MeLi) and commutation (NMe2 DADBs) reactions, thus making the DADB system a general structural motif in diborane(4) chemistry. A total of 18 DADB derivatives were characterized in the solid state by X-ray diffraction, revealing a strong dependence of the heterocyclic bonding parameters from the exocyclic substitution pattern at boron. According to our experiments towards the realization of a Dipp-substituted, sterically encumbered DADB, the mechanism of DADB formation proceeds via a transient four-membered azadiboretidine intermediate that subsequently undergoes ring expansion to afford the six-membered DADB heterocycle.
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Affiliation(s)
- Torsten Thiess
- Institute of Inorganic ChemistryJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
- Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Moritz Ernst
- Institute of Inorganic ChemistryJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
- Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Thomas Kupfer
- Institute of Inorganic ChemistryJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
- Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Holger Braunschweig
- Institute of Inorganic ChemistryJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
- Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
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37
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Song BR, Ha MW, Kim D, Park C, Lee KW, Paek SM. Investigation of Grignard Reagent as an Advanced Base for Aza-Claisen Rearrangement. Molecules 2019; 24:E4597. [PMID: 31888158 DOI: 10.3390/molecules24244597] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 12/09/2019] [Accepted: 12/12/2019] [Indexed: 11/16/2022] Open
Abstract
Employing iPrMgCl as an advanced base instead of lithium hexamethyldisilazane (LHMDS) resulted in dramatic improvements in aza-Claisen rearrangement. This advance is considered responsible for the increased bulkiness of the alkoxide moiety (including magnesium cation and ligands), followed by a resultant conformational change of the transition state. To support this hypothesis, various substrates of aza-Claisen rearrangement were prepared and screened. In addition, a molecular dynamic simulation study was performed to investigate and compare the structural stability of reaction intermediates.
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38
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Wang XB, Zheng ZJ, Xie JL, Gu XW, Mu QC, Yin GW, Ye F, Xu Z, Xu LW. Controllable Si-C Bond Activation Enables Stereocontrol in the Palladium-Catalyzed [4+2] Annulation of Cyclopropenes with Benzosilacyclobutanes. Angew Chem Int Ed Engl 2019; 59:790-797. [PMID: 31829499 DOI: 10.1002/anie.201913060] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Indexed: 12/15/2022]
Abstract
A novel and unusual palladium-catalyzed [4+2] annulation of cyclopropenes with benzosilacyclobutanes is reported. This reaction occurred through chemoselective Si-C(sp2 ) bond activation in synergy with ring expansion/insertion of cyclopropenes to form new C(sp2 )-C(sp3 ) and Si-C(sp3 ) bonds. An array of previously elusive bicyclic skeleton with high strain, silabicyclo[4.1.0]heptanes, were formed in good yields with excellent diastereoselectivity under mild conditions. An asymmetric version of the reaction with a chiral phosphoramidite ligand furnished a variety of chiral bicyclic silaheterocycle derivatives with good enantioselectivity (up to 95.5:4.5 er). Owing to the mild reaction conditions, the good stereoselectivity profile, and the ready availability of the functionalized precursors, this process constitutes a useful and straightforward strategy for the synthesis of densely functionalized silacycles.
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Affiliation(s)
- Xing-Ben Wang
- Key Laboratory of Organosilicon Chemistry and Material Technology of the Ministry of Education, Hangzhou Normal University, No. 2318, Yuhangtang Road, Hangzhou, 311121, P. R. China
| | - Zhan-Jiang Zheng
- Key Laboratory of Organosilicon Chemistry and Material Technology of the Ministry of Education, Hangzhou Normal University, No. 2318, Yuhangtang Road, Hangzhou, 311121, P. R. China
| | - Jia-Le Xie
- Key Laboratory of Organosilicon Chemistry and Material Technology of the Ministry of Education, Hangzhou Normal University, No. 2318, Yuhangtang Road, Hangzhou, 311121, P. R. China
| | - Xing-Wei Gu
- Key Laboratory of Organosilicon Chemistry and Material Technology of the Ministry of Education, Hangzhou Normal University, No. 2318, Yuhangtang Road, Hangzhou, 311121, P. R. China
| | - Qiu-Chao Mu
- Key Laboratory of Organosilicon Chemistry and Material Technology of the Ministry of Education, Hangzhou Normal University, No. 2318, Yuhangtang Road, Hangzhou, 311121, P. R. China
| | - Guan-Wu Yin
- Key Laboratory of Organosilicon Chemistry and Material Technology of the Ministry of Education, Hangzhou Normal University, No. 2318, Yuhangtang Road, Hangzhou, 311121, P. R. China
| | - Fei Ye
- Key Laboratory of Organosilicon Chemistry and Material Technology of the Ministry of Education, Hangzhou Normal University, No. 2318, Yuhangtang Road, Hangzhou, 311121, P. R. China
| | - Zheng Xu
- Key Laboratory of Organosilicon Chemistry and Material Technology of the Ministry of Education, Hangzhou Normal University, No. 2318, Yuhangtang Road, Hangzhou, 311121, P. R. China
| | - Li-Wen Xu
- Key Laboratory of Organosilicon Chemistry and Material Technology of the Ministry of Education, Hangzhou Normal University, No. 2318, Yuhangtang Road, Hangzhou, 311121, P. R. China.,Suzhou Research Institute and State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, P. R. China
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39
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Rao B, Kinjo R. A Cyclic (Alkyl)(boryl)germylene Derived from a Cyclic (Alkyl)(amino)germylene. Angew Chem Int Ed Engl 2019; 58:18150-18153. [PMID: 31596041 DOI: 10.1002/anie.201910933] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 09/29/2019] [Indexed: 11/09/2022]
Abstract
A cyclic (alkyl)(amino)germylene undergoes a ring expansion reaction with dibromomesitylborane (MesBBr2 ) to afford a six-membered dibromogermane derivative. In the presence of Lewis bases (PMe3 or Me NHC), reduction of the latter with two equivalents of potassium graphite (KC8 ) gives rise to cyclic (alkyl)(boryl)germylene-Lewis base adducts. Upon heating, the germylene-PMe3 adduct reacts with H2 to yield a germane, probably via a base-free germylene featuring a small HOMO-LUMO gap.
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Affiliation(s)
- Bin Rao
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Nanyang Link 21, Singapore, 637371, Singapore
| | - Rei Kinjo
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Nanyang Link 21, Singapore, 637371, Singapore
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40
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Choi G, Jo S, Mun J, Jeong Y, Kim SH, Jung JW. Unexpected Rearrangement of N-Allyl-2-phenyl-4,5-Dihydrooxazole-4-Carboxamides to Construct Aza-Quaternary Carbon Centers. Molecules 2019; 24:E4495. [PMID: 31817984 DOI: 10.3390/molecules24244495] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 12/01/2019] [Accepted: 12/06/2019] [Indexed: 11/21/2022] Open
Abstract
The unexpected rearrangement of N-allyl-2-phenyl-4,5-dihydrooxazole-4-carboxamides in the presence of LiHMDS has been found. The key features are: (1) the net reaction consisted of 1,3-migration of the N-allyl group, (2) the rearrangement produced a congested aza-quaternary carbon center, (3) both cyclic and acyclic substrates underwent the unexpected rearrangement to afford products in moderate to high yields, and (4) the reaction seemed to be highly stereoselective. In addition, a plausible mechanism has been discussed.
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41
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Dierks A, Tönjes J, Schmidtmann M, Christoffers J. Synthesis of Benzo[b]azocin-2-ones by Aryl Amination and Ring-Expansion of α-(Iodophenyl)-β-oxoesters. Chemistry 2019; 25:14912-14920. [PMID: 31433088 PMCID: PMC6899745 DOI: 10.1002/chem.201903139] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Indexed: 01/16/2023]
Abstract
Transformation of β-oxoesters with PhI(OCOCF3 )2 leads to α-(ortho-iodophenyl)-β-oxoesters. These materials are the starting point for the synthesis of 6-carboxybenzo[b]azocin-2-ones by a sequence of aryl amination and ring transformation. This reaction sequence starts with copper-catalyzed formation of N-alkyl anilines from the iodoarenes and primary amines in the presence of K3 PO4 as stoichiometric base. The intermediate products underwent ring transformation by addition of the nitrogen into the carbonyl group of the cycloalkanone, furnishing benzo-annulated eight-membered ring lactams. Under the same reaction conditions, the cyclohexanone and cycloheptanone derivatives gave no aminated products, but ring-transformed to benzofuran derivatives. The title compounds of this investigation contain two points for further diversification (the lactam nitrogen and the carboxylate function), thus, the suitability of this compound class as a scaffold was proven by appropriate functionalizations. The first series of derivatizations of the scaffold was initiated by hydrogenolytic debenzylation of N-benzyl derivative to provide the NH-congener, which could be deprotonated with LDA and alkylated at nitrogen to give further examples of this compound class. Secondly, the ester function was submitted to saponification and the resulting carboxylic acid could be amidated using HATU as coupling reagent to furnish different amides.
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Affiliation(s)
- Anna Dierks
- Institut für ChemieCarl von Ossietzky Universität Oldenburg26111OldenburgGermany
| | - Jan Tönjes
- Institut für ChemieCarl von Ossietzky Universität Oldenburg26111OldenburgGermany
| | - Marc Schmidtmann
- Institut für ChemieCarl von Ossietzky Universität Oldenburg26111OldenburgGermany
| | - Jens Christoffers
- Institut für ChemieCarl von Ossietzky Universität Oldenburg26111OldenburgGermany
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42
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Cala L, Rivilla I, Cossío FP, Fañanás FJ, Rodríguez F. Synthesis of Sultones from Chlorosulfates by a Complex Cascade Reaction Occurring under Mild Thermal Conditions. Chemistry 2019; 25:13083-13087. [PMID: 31379026 DOI: 10.1002/chem.201903228] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Indexed: 01/30/2023]
Abstract
Chlorosulfate derivatives are interesting reagents that have been traditionally used to get other sulfur-containing compounds by formal nucleophilic substitution of the chlorine atom. This work describes a different mode of reactivity of alkyne-containing chlorosulfates to get sultones, the sulfur analogues of lactones. The complex skeletal rearrangement observed in this transformation is comparable to those intricate processes promoted or catalyzed by organometallic compounds. However, the reaction here described does not require any reagent or additive, being just a thermal process. Computational calculations support a mechanism based on a series of cascade reactions where almost every step is counterintuitive. Some of these steps include original processes related to classical reactions, thus adding complementary views to traditional organic chemistry.
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Affiliation(s)
- Lara Cala
- Instituto Universitario de Química Organometálica "Enrique Moles", Universidad de Oviedo, Julián Clavería, 8, 33006, Oviedo, Spain
| | - Iván Rivilla
- Departamento de Química Orgánica I, Universidad del, País Vasco (UPV/EHU) and Donostia International Physics Center (DIPC), P. K. 1072, 20080, San Sebastián, Spain
| | - Fernando P Cossío
- Departamento de Química Orgánica I, Universidad del, País Vasco (UPV/EHU) and Donostia International Physics Center (DIPC), P. K. 1072, 20080, San Sebastián, Spain
| | - Francisco J Fañanás
- Instituto Universitario de Química Organometálica "Enrique Moles", Universidad de Oviedo, Julián Clavería, 8, 33006, Oviedo, Spain
| | - Félix Rodríguez
- Instituto Universitario de Química Organometálica "Enrique Moles", Universidad de Oviedo, Julián Clavería, 8, 33006, Oviedo, Spain
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43
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Liang Y, Pan JL, Sun LH, Ma JM, Jiang H, Li ZL. Alternating Sequence Control for Poly(ester amide)s by Organocatalyzed Ring-Opening Polymerization. Macromol Rapid Commun 2019; 40:e1900435. [PMID: 31596528 DOI: 10.1002/marc.201900435] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 09/18/2019] [Indexed: 12/21/2022]
Abstract
Sequence-controlled polymerization is the forefront of polymer chemistry. Herein, the feasibility of sequence regulation by using organocatalyzed ring-opening polymerization (ROP) is demonstrated. In particular, ring expansion strategy is employed to synthesize pre-organized monomers 1 and 2. ROP is conducted by using 1,5,7-triazabicyclo[4.4.0]dec-5-ene and benzyl alcohol as the catalyst and initiator, respectively. Poly(ester amide)s (PEAs) P1-P3 comprising glycolic acid, lactic acid, and 7-aminoheptanoic acid units are obtained in high molecular weights and good yields. NMR and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry results verify the microstructural integrity of P1 and P2. Differential scanning calorimetry results show that PEA without methyl branches is crystalline. Moreover, thermal stability, surface wettability, and degradation profiles of P1-P3 are also investigated.
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Affiliation(s)
- Yang Liang
- Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Jun-Lin Pan
- Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Lin-Hao Sun
- Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Ji-Mei Ma
- Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Hong Jiang
- Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Zi-Long Li
- Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
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44
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Abstract
The reaction of the phosphinidene complex [Cp*P{W(CO)5 }2 ] (1 a) (Cp*=C5 Me5 ) with the anionic cyclo-Pn ligand complex [(η3 -P3 )Nb(ODipp)3 ]- (2, Dipp=2,6-diisopropylphenyl) resulted in the formation of [{W(CO)5 }2 {μ3 ,η3:1:1 -P4 Cp*}Nb(ODipp)3 ]- (3), which represents an unprecedented example of a ring expansion of a polyphosphorus-ligand complex initiated by a phosphinidene complex. Furthermore, the reaction of the pnictinidene complexes [Cp*E{W(CO)5 }2 ] (E=P: 1 a, As: 1 b) with the neutral complex [Cp'''Co(η4 -P4 )] (Cp'''=1,2,4-tBu3 C5 H2 ) led to a cyclo-P4 E ring (E=P, As) through the insertion of the pentel atom into the cyclo-P4 ligand. Starting from 1 a, the two isomers [Cp'''Co(μ3 ,η4:1:1 -P5 Cp*){W(CO)5 }2 ] (5 a,b), and from 1 b, the three isomers [Cp'''Co(μ3 ,η4:1:1 -AsP4 Cp*){W(CO)5 }2 ] (6 a-c) with unprecedented cyclo-P4 E ligands (E=P, As) were isolated. The complexes 6 a-c represent unique examples of ring expansions which lead to new mixed five-membered cyclo-P4 As ligands. The possible reaction pathways for the formation of 5 a,b and 6 a-c were investigated by a combination of temperature-dependent 31 P{1 H} NMR studies and DFT calculations.
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Affiliation(s)
- Martin Piesch
- Institute of Inorganic Chemistry, University of Regensburg, 93040, Regensburg, Germany
| | - Michael Seidl
- Institute of Inorganic Chemistry, University of Regensburg, 93040, Regensburg, Germany
| | - Markus Stubenhofer
- Institute of Inorganic Chemistry, University of Regensburg, 93040, Regensburg, Germany
| | - Manfred Scheer
- Institute of Inorganic Chemistry, University of Regensburg, 93040, Regensburg, Germany
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45
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Wu A, Feng Q, Sung HHY, Williams ID, Sun J. Synthesis of Eight-Membered Lactams through Formal [6+2] Cyclization of Siloxy Alkynes and Vinylazetidines. Angew Chem Int Ed Engl 2019; 58:6776-6780. [PMID: 30888103 DOI: 10.1002/anie.201902866] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Indexed: 12/31/2022]
Abstract
A new approach for the efficient synthesis of eight-membered lactams through formal [6+2] cyclization of siloxy alkynes and vinylazetidines has been developed. Evidence from a chirality transfer experiment suggests that the reaction proceeds via a [3,3]-sigmatropic rearrangement from a ketene intermediate. This insight led to the development of alternative conditions and use of acyl chlorides as ketene precursors for the [6+2] reaction with vinylazetidines.
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Affiliation(s)
- An Wu
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Qiang Feng
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Herman H Y Sung
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Ian D Williams
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Jianwei Sun
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
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46
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Ueda M, Tahara A, Hasegawa M, Shirahata T, Mazaki Y, Misaki Y. Hydration of Polycationic [5]Radialene with Quintuple 1,3-Dithiol-2-ylidenes Leads to a New Class of π-Extended Tetrathiafulvalene Scaffold. Chemistry 2019; 25:4984-4991. [PMID: 30636026 DOI: 10.1002/chem.201805994] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 01/10/2019] [Indexed: 11/07/2022]
Abstract
[5]Radialene with quintuple 4,5-benzo-1,3-dithiol-2-ylidenes (DTs) easily forms a stable polycationic salt (1)4+ (BF4 - )4 owing to its aromatic character in the central cyclopentadienide ring. In this work, it was found that the polycationic salt (1)4+ underwent a hydration reaction in moist polar solvent to give several unexpected products, namely, an oxygen adduct dicationic salt (2)2+ , a tetrathiafulvalene (TTF) vinylogue (3) with 1,4-dithiine-2(3H)-one moieties, and an oxygen adduct of π-extended TTF with a cyclopentenone core (4). Their molecular structures were fully determined by X-ray crystal-structure analysis. In this reaction, irreversible hydration to the polycationic salt might either initiate the ring expansion and lead to the successive hydration at the specific cationic DT ring (for 3), or promote the transannular reactions to the next DT ring followed by elimination of the DT ring (for 4). Cyclic voltammetry and differential pulse voltammetry measurements for compound 3 indicated the occurrence of multi redox process resulting from electronic delocalization on the vinylogous TTF moiety. The electronic structures of the cationic species of 3 were also investigated by electronic spectra.
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Affiliation(s)
- Masafumi Ueda
- Department of Applied Chemistry, Graduate School of Engineering, Ehime University, 3-Bunkyo-cho Matsuyama, Ehime, 790-8577, Japan
| | - Akimi Tahara
- Department of Applied Chemistry, Graduate School of Engineering, Ehime University, 3-Bunkyo-cho Matsuyama, Ehime, 790-8577, Japan
| | - Masashi Hasegawa
- Department of Chemistry, School of Science, Kitasato University, 1-15-1 Kitasato Minami-ku Sagamihara, Kanagawa, 252-0373, Japan
| | - Takashi Shirahata
- Department of Applied Chemistry, Graduate School of Engineering, Ehime University, 3-Bunkyo-cho Matsuyama, Ehime, 790-8577, Japan.,Research Unit for Power Generation and Storage Materials, and Research Unit for Development of Organic Superconductors, Ehime University, Matsuyama, Ehime, 790-8577, Japan
| | - Yasuhiro Mazaki
- Department of Chemistry, School of Science, Kitasato University, 1-15-1 Kitasato Minami-ku Sagamihara, Kanagawa, 252-0373, Japan
| | - Yohji Misaki
- Department of Applied Chemistry, Graduate School of Engineering, Ehime University, 3-Bunkyo-cho Matsuyama, Ehime, 790-8577, Japan.,Research Unit for Power Generation and Storage Materials, and Research Unit for Development of Organic Superconductors, Ehime University, Matsuyama, Ehime, 790-8577, Japan
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47
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Abstract
Disclosed is a five-step synthesis of (±)-vibralactone, a biologically active terpenoid natural product. A key photochemical valence isomerization of 3-prenyl-pyran-2-one produces both the all-carbon quaternary stereocenter and the β-lactone at an early stage. Cyclopropanation of the resulting bicyclic β-lactone produces a strained housane structure that is converted to the natural product through a sequential ring expansion and reduction strategy. This concise and modular route to the natural product provides the shortest total synthesis of (±)-vibralactone reported to date.
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Affiliation(s)
- Sepand K Nistanaki
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Luke A Boralsky
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Roy D Pan
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Hosea M Nelson
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095, USA
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48
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Zhou Y, Wei YL, Rodriguez J, Coquerel Y. Enantioselective Organocatalytic Four-Atom Ring Expansion of Cyclobutanones: Synthesis of Benzazocinones. Angew Chem Int Ed Engl 2018; 58:456-460. [PMID: 30398303 DOI: 10.1002/anie.201810184] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 10/15/2018] [Indexed: 01/04/2023]
Abstract
An enantioselective Michael addition- four-atom ring expansion cascade reaction involving cyclobutanones activated by a N-aryl secondary amide group and ortho-amino nitrostyrenes has been developed for the preparation of functionalized eight-membered benzolactams using bifunctional aminocatalysts. Taking advantage of the secondary amide activating group, the eight-membered cyclic products could be further rearranged into their six-membered isomers having a glutarimide core under base catalysis conditions without erosion of optical purity, featuring an overall ring expansion- ring contraction strategy.
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Affiliation(s)
- Yirong Zhou
- Aix Marseille Université, CNRS, Centrale Marseille, ISM2, 13397, Marseille, France.,Key Laboratory of Functional Small Organic Molecules Ministry of Education, Jiangxi Normal University, 330022, Nanchang, China
| | - Yun-Long Wei
- Aix Marseille Université, CNRS, Centrale Marseille, ISM2, 13397, Marseille, France
| | - Jean Rodriguez
- Aix Marseille Université, CNRS, Centrale Marseille, ISM2, 13397, Marseille, France
| | - Yoann Coquerel
- Aix Marseille Université, CNRS, Centrale Marseille, ISM2, 13397, Marseille, France
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49
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Stephens TC, Lawer A, French T, Unsworth WP. Iterative Assembly of Macrocyclic Lactones using Successive Ring Expansion Reactions. Chemistry 2018; 24:13947-13953. [PMID: 30011360 PMCID: PMC6334170 DOI: 10.1002/chem.201803064] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 07/12/2018] [Indexed: 12/27/2022]
Abstract
Macrocyclic lactones can be prepared from lactams and hydroxyacid derivatives via an efficient 3- or 4-atom iterative ring expansion protocol. The products can also be expanded using amino acid-based linear fragments, meaning that macrocycles with precise sequences of hydroxy- and amino acids can be assembled in high yields by "growing" them from smaller rings, using a simple procedure in which high dilution is not required. The method should significantly expedite the practical synthesis of diverse nitrogen containing macrolide frameworks.
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50
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Guney T, Wenderski TA, Boudreau MW, Tan DS. Synthesis of Benzannulated Medium-ring Lactams via a Tandem Oxidative Dearomatization- Ring Expansion Reaction. Chemistry 2018; 24:13150-13157. [PMID: 29936701 PMCID: PMC6242278 DOI: 10.1002/chem.201802880] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Indexed: 12/19/2022]
Abstract
Medium-ring natural products exhibit diverse biological activities but such scaffolds are underrepresented in probe and drug discovery efforts due to the limitations of classical macrocyclization reactions. We report herein a tandem oxidative dearomatization-ring-expanding rearomatization (ODRE) reaction that generates benzannulated medium-ring lactams directly from simple bicyclic substrates. The reaction accommodates diverse aryl substrates (haloarenes, aryl ethers, aryl amides, heterocycles) and strategic incorporation of a bridgehead alcohol generates a versatile ketone moiety in the products amenable to downstream modifications. Cheminformatic analysis indicates that these medium rings access regions of chemical space that overlap with related natural products and are distinct from synthetic drugs, setting the stage for their use in discovery screening against novel biological targets.
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Affiliation(s)
- Tezcan Guney
- Dr. T. Guney, Dr. T. A. W enderski, Prof. Dr. D. S. Tan,
Chemical Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer
Center, 1275 York Avenue, Box 422, New York, New York, 10065, USA
| | - Todd A. Wenderski
- Dr. T. Guney, Dr. T. A. W enderski, Prof. Dr. D. S. Tan,
Chemical Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer
Center, 1275 York Avenue, Box 422, New York, New York, 10065, USA
| | - Matthew W. Boudreau
- M. W. Boudreau, Gerstner Sloan Kettering Summer
Undergraduate Research Program, Memorial Sloan Kettering Cancer Center, 1275 York
Avenue, Box 422, New York, New York, 10065, USA
| | - Derek S. Tan
- Dr. T. Guney, Dr. T. A. W enderski, Prof. Dr. D. S. Tan,
Chemical Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer
Center, 1275 York Avenue, Box 422, New York, New York, 10065, USA
- Prof. Dr. D. S. Tan, Tri-Institutional Research Program,
Memorial Sloan Kettering Cancer Center, 1275 York Avenue, Box 422, New York, New
York, 10065, USA
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