1
|
Li S, Zhou L. Photocatalytic (3 + 3) Annnulation of Vinyldiazo Compounds and Aminocyclopropanes. Org Lett 2024; 26:3294-3298. [PMID: 38567829 DOI: 10.1021/acs.orglett.4c00963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2024]
Abstract
A (3 + 3) annulation of aminocyclopropanes and vinyldiazo compounds enabled by organo-photocatalysis is described. The reaction allows the regioselective synthesis of cyclohexenes bearing adjacent amino and carbonyl groups with broad functional group tolerance. In a departure from previous reports, our work demonstrated that a distonic radical cation can be preferentially intercepted by weakly nucleophilic vinyldiazo compounds, followed by an exclusive 6-endo radical cyclization for ring closure. Based on the interaction between adjacent amino and ester groups, the products can be further converted to cyclohexene-fused 1,3-oxazinane and azetidine.
Collapse
Affiliation(s)
- Sen Li
- Institute of Green Chemistry and Molecular Engineering, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Lei Zhou
- Institute of Green Chemistry and Molecular Engineering, School of Chemistry, Sun Yat-Sen University, Guangzhou, 510275, China
| |
Collapse
|
2
|
Niu SS, Liu Y, Zhang Y, Li XC, Gong J, Ding W, Cheng Y. Experimental and Theoretical Study on the Regioselective Radical Cyclization Reactions of 1-( o-Alkenylaryl)-2-amido-1-ketones for the Construction of Indeno[2,1- d][1,3]oxazin-9-ones. J Org Chem 2022; 87:9576-9592. [PMID: 35820108 DOI: 10.1021/acs.joc.2c00567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A simple and efficient two-step method for the construction of novel 2,4,9a-trisubstituted-4a,9a-dihydroindeno[2,1-d][1,3]oxazin-9-ones has been developed. The NHC-catalyzed aza-benzoin reaction of o-alkenyl benzaldehydes with N-acylarylimines afforded 1-(o-alkenylaryl)-2-amido-2-aryl-1-ethanones, which underwent regioselective 5-exo-trig radical cyclization to furnish the three-ring-fused heterocyclic products, generally in good yields. The synthetic method displayed good tolerance toward the nature of substituents, substitution pattern, and steric hindrance of o-alkenyl benzaldehydes. Based on this method, the synthesis of unprecedented dihydrobenzo[6,7]indeno[2,1-d][1,3]oxazin-7-ones and dihydropyrido[2',3':3,4]cyclopenta[1,2-d][1,3]oxazin-9-ones has been achieved by employing o-alkenylnaphthaldehyde and o-alkenylnicotinaldehyde as substrates. The regioselectivity between 5-exo-trig and 6-endo-trig radical cyclization reactions of different 1-(o-alkenylaryl)-2-amido-2-aryl-1-ethanones were elucidated with DFT calculations.
Collapse
Affiliation(s)
- Shuang-Shuo Niu
- College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Yimin Liu
- College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Yue Zhang
- College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Xing-Chi Li
- College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Jian Gong
- College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Wanjian Ding
- College of Chemistry, Beijing Normal University, Beijing 100875, China
| | - Ying Cheng
- College of Chemistry, Beijing Normal University, Beijing 100875, China
| |
Collapse
|
3
|
Maust MC, Hendy CM, Jui NT, Blakey SB. Switchable Regioselective 6- endo or 5- exo Radical Cyclization via Photoredox Catalysis. J Am Chem Soc 2022; 144:3776-3781. [PMID: 35200024 PMCID: PMC8925928 DOI: 10.1021/jacs.2c00192] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Controlling the regioselectivity of radical cyclizations to favor the 6-endo mode over its kinetically preferred 5-exo counterpart is difficult without introducing substrate prefunctionalization. To address this challenge, we have developed a simple method for reagent controlled regioselective radical cyclization of halogenated N-heterocycles onto pendant olefins. Radical generation occurs under mild photoredox conditions with control of the regioselectivity governed by the rate of hydrogen atom transfer (HAT). Utilizing a polarity-matched thiol-based HAT agent promotes the highly selective formation of the 5-exo cyclization product. Conversely, limiting the solubility of the HAT reagent Hantzsch ester (HEH) leads to selective formation of the thermodynamically favored 6-endo product. This occurs through an initial 5-exo cyclization, with the resulting alkyl radical intermediate undergoing neophyl rearrangement to form the 6-endo product. Development of this switchable catalysis strategy allows for two modes of divergent reactivity to form either the 6-endo or 5-exo product, generating fused N-heteroaromatic/saturated ring systems.
Collapse
Affiliation(s)
- Mark C Maust
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Cecilia M Hendy
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Nathan T Jui
- Loxo Oncology, Boulder, Colorado 80301, United States
| | - Simon B Blakey
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| |
Collapse
|
4
|
Tomanik M, Xu Z, Guo F, Wang Z, Yang KR, Batista VS, Herzon SB. Development of an Enantioselective Synthesis of (-)-Euonyminol. J Org Chem 2021; 86:17011-17035. [PMID: 34784213 DOI: 10.1021/acs.joc.1c02167] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We detail the development of the first enantioselective synthetic route to euonyminol (1), the most heavily oxidized member of the dihydro-β-agarofuran sesquiterpenes and the nucleus of the macrocyclic alkaloids known as the cathedulins. Key steps in the synthetic sequence include a novel, formal oxyalkylation reaction of an allylic alcohol by [3 + 2] cycloaddition; a tandem lactonization-epoxide opening reaction to form the trans-C2-C3 vicinal diol residue; and a late-stage diastereoselective trimethylaluminum-mediated α-ketol rearrangement. We report an improved synthesis of the advanced unsaturated ketone intermediate 64 by means of a 6-endo-dig radical cyclization of the enyne 42. This strategy nearly doubled the yield through the intermediate steps in the synthesis and avoided a problematic inversion of stereochemistry required in the first-generation approach. Computational studies suggest that the mechanism of this transformation proceeds via a direct 6-endo-trig cyclization, although a competing 5-exo-trig cyclization, followed by a rearrangement, is also energetically viable. We also detail the challenges associated with manipulating the oxidation state of late-stage intermediates, which may inform efforts to access other derivatives such as 9-epi-euonyminol or 8-epi-euonyminol. Our successful synthetic strategy provides a foundation to synthesize the more complex cathedulins.
Collapse
Affiliation(s)
- Martin Tomanik
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Zhi Xu
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Facheng Guo
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States.,Energy Sciences Institute, Yale University, West Haven, Connecticut 06516, United States
| | - Zechun Wang
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
| | - Ke R Yang
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States.,Energy Sciences Institute, Yale University, West Haven, Connecticut 06516, United States
| | - Victor S Batista
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States.,Energy Sciences Institute, Yale University, West Haven, Connecticut 06516, United States
| | - Seth B Herzon
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States.,Department of Pharmacology, Yale School of Medicine, New Haven, Connecticut 06520, United States
| |
Collapse
|
5
|
Xuan J, Studer A. Radical cascade cyclization of 1,n-enynes and diynes for the synthesis of carbocycles and heterocycles. Chem Soc Rev 2017; 46:4329-4346. [DOI: 10.1039/c6cs00912c] [Citation(s) in RCA: 261] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
This review highlights recent advances in radical cascade cyclization of 1,n-enynes and diynes for the construction of carbo- and heterocycles.
Collapse
Affiliation(s)
- Jun Xuan
- Department of Chemistry
- Anhui University
- Hefei
- People's Republic of China
| | - Armido Studer
- Institute of Organic Chemistry
- Westfälische Wilhems-University
- 48149 Münster
- Germany
| |
Collapse
|
6
|
Katayama A, Senboku H. Sequential Vinyl Radical Cyclization/Fixation of Carbon Dioxide through Electrochemical Reduction of Vinyl Bromide in the Presence of an Electron-Transfer Mediator. ChemElectroChem 2016. [DOI: 10.1002/celc.201600508] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Asahi Katayama
- Graduate School of Chemical Sciences and Engineering; Hokkaido University; Kita 13 Nishi 8, Kita-ku, Sapporo Hokkaido 060-8628 Japan
| | - Hisanori Senboku
- Faculty of Engineering; Hokkaido University; Kita 13 Nishi 8, Kita-ku, Sapporo Hokkaido 060-8628 Japan
| |
Collapse
|
7
|
Catalytic N-radical cascade reaction of hydrazones by oxidative deprotonation electron transfer and TEMPO mediation. Nat Commun 2016; 7:11188. [PMID: 27048886 PMCID: PMC4823831 DOI: 10.1038/ncomms11188] [Citation(s) in RCA: 176] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 02/25/2016] [Indexed: 12/22/2022] Open
Abstract
Compared with the popularity of various C-centred radicals, the N-centred radicals remain largely unexplored in catalytic radical cascade reactions because of a lack of convenient methods for their generation. Known methods for their generation typically require the use of N-functionalized precursors or various toxic, potentially explosive or unstable radical initiators. Recently, visible-light photocatalysis has emerged as an attractive tool for the catalytic formation of N-centred radicals, but the pre-incorporation of a photolabile groups at the nitrogen atom largely limited the reaction scope. Here, we present a visible-light photocatalytic oxidative deprotonation electron transfer/2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-mediation strategy for catalytic N-radical cascade reaction of unsaturated hydrazones. This mild protocol provides a broadly applicable synthesis of 1,6-dihydropyradazines with complete regioselectivity and good yields. The 1,6-dihydropyradazines can be easily transformed into diazinium salts that showed promising in vitro antifungal activities against fungal pathogens. DFT calculations are conducted to explain the mechanism. The use of N-centred radicals is limited by the difficulties in their preparation. Here, the authors report a photoredox method for the formation of N-centred radicals on hydrazones and their use for the synthesis of heterocyclic compounds through a radical cascade reaction.
Collapse
|
8
|
Valerio V, Mostinski Y, Kotikalapudi R, Tsvelikhovsky D. Stereo- and Regioselective Synthesis of Tricyclic Spirolactones by Diastereoisomeric Differentiation of a Collective Key Precursor. Chemistry 2016; 22:2640-7. [PMID: 26752216 DOI: 10.1002/chem.201504310] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Indexed: 11/09/2022]
Abstract
A general, parallel, and collective synthesis of 5/5/5- and 5/5/6-ring fusion topologies of tricyclic spiranoid lactones through the controlled cyclizations of easily accessible, common key precursors is described. The rapid composition of key cycloalkyl methylene precursors yielded an assembly of bicyclic diastereoisomeric iodolactones, which were individually converted into a wide range of tricyclic, angularly fused spiranoid lactones in a regioselective and stereodirected fashion through the diastereoisomeric differentiation of a collective key precursor. The critical stereochemical assignment of the bicyclic starting materials, as well as the tricyclic targets, was confirmed by X-ray crystal structure determination.
Collapse
Affiliation(s)
- Viviana Valerio
- The Institute for Drug Research, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, 91120, Israel
| | - Yelena Mostinski
- The Institute for Drug Research, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, 91120, Israel
| | - Ramesh Kotikalapudi
- The Institute for Drug Research, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, 91120, Israel
| | - Dmitry Tsvelikhovsky
- The Institute for Drug Research, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, 91120, Israel.
| |
Collapse
|
9
|
Wille U. Radical Cascades Initiated by Intermolecular Radical Addition to Alkynes and Related Triple Bond Systems. Chem Rev 2012; 113:813-53. [DOI: 10.1021/cr100359d] [Citation(s) in RCA: 465] [Impact Index Per Article: 38.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Uta Wille
- School of Chemistry and
BIO21 Molecular Science and
Biotechnology Institute, Australian Research Council Centre of Excellence
for Free Radical Chemistry and Biotechnology, The University of Melbourne, 30 Flemington Road, Parkville, Victoria
3010, Australia
| |
Collapse
|
10
|
Karimiahmadabadi M, Erfan S, Földesi A, Chattopadhyaya J. Steric Effects in the Tuning of the Diastereoselectivity of the Intramolecular Free-Radical Cyclization to an Olefin As Exemplified through the Synthesis of a Carba-Pentofuranose Scaffold. J Org Chem 2012; 77:6855-72. [DOI: 10.1021/jo300936g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Mansoureh Karimiahmadabadi
- Program of
Chemical Biology, Department of Cell and
Molecular Biology, Biomedical Centre, Uppsala University, SE-75123 Uppsala, Sweden
| | - Sayeh Erfan
- Program of
Chemical Biology, Department of Cell and
Molecular Biology, Biomedical Centre, Uppsala University, SE-75123 Uppsala, Sweden
| | - Andras Földesi
- Program of
Chemical Biology, Department of Cell and
Molecular Biology, Biomedical Centre, Uppsala University, SE-75123 Uppsala, Sweden
| | - Jyoti Chattopadhyaya
- Program of
Chemical Biology, Department of Cell and
Molecular Biology, Biomedical Centre, Uppsala University, SE-75123 Uppsala, Sweden
| |
Collapse
|
11
|
Gómez AM, Uriel C, Company MD, López JC. Synthetic Strategies Directed Towards 5a-Carbahexopyranoses and Derivatives Based on 6-endo-trig Radical Cyclizations. European J Org Chem 2011. [DOI: 10.1002/ejoc.201100956] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
|
12
|
Ram RN, Tittal RK, Upreti S. An unusual decarboxylative benzannulation and biaryl formation during copper(I)-promoted halogen atom transfer radical cyclization of 2-allylaryl trichloroacetates. Tetrahedron Lett 2007. [DOI: 10.1016/j.tetlet.2007.09.058] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|