1
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Liu Y, Zhu Z, Zhang Y, Zhang Y, Liu S, Shen X. Stereoselective Synthesis of Silyl Enol Ethers with Acylsilanes and α,β-Unsaturated Ketones. Org Lett 2024. [PMID: 38975934 DOI: 10.1021/acs.orglett.4c01782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/09/2024]
Abstract
Acylsilanes are emerging bench-stable reagents for the generation of electron-rich oxycarbenes that are difficult to access with unstable diazo compounds. Herein, we report a siloxycarbene-mediated stereoselective synthesis of silyl enol ethers through visible-light-induced intermolecular reactions between acylsilanes and α,β-unsaturated ketones. Both the solvent and low temperature are important for the success of the reaction. This approach features atomic economics, exclusive stereocontrol, and broad substrate scope. The synthetic potential of this methodology is demonstrated by gram-scale reaction and various downstream transformations including that requiring configuration purity of the silyl enol ethers.
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Affiliation(s)
- Ying Liu
- The Institute for Advanced Studies, Engineering Research Center of Organosilicon Compounds & Materials, Ministry of Education, Wuhan University, 299 Bayi Road, Wuhan, Hubei 430072, China
| | - Zhihong Zhu
- The Institute for Advanced Studies, Engineering Research Center of Organosilicon Compounds & Materials, Ministry of Education, Wuhan University, 299 Bayi Road, Wuhan, Hubei 430072, China
| | - Yunxiao Zhang
- The Institute for Advanced Studies, Engineering Research Center of Organosilicon Compounds & Materials, Ministry of Education, Wuhan University, 299 Bayi Road, Wuhan, Hubei 430072, China
| | - Yizhi Zhang
- The Institute for Advanced Studies, Engineering Research Center of Organosilicon Compounds & Materials, Ministry of Education, Wuhan University, 299 Bayi Road, Wuhan, Hubei 430072, China
| | - Shanshan Liu
- The Institute for Advanced Studies, Engineering Research Center of Organosilicon Compounds & Materials, Ministry of Education, Wuhan University, 299 Bayi Road, Wuhan, Hubei 430072, China
| | - Xiao Shen
- The Institute for Advanced Studies, Engineering Research Center of Organosilicon Compounds & Materials, Ministry of Education, Wuhan University, 299 Bayi Road, Wuhan, Hubei 430072, China
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2
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Adhikari P, Hazarika N, Bhattacharyya K, Das A. Chromium-Catalyzed Cross-Coupling of Methyl Ketones with Cyclic Ketones toward the Selective Synthesis of β-Branched β,γ-Unsaturated Ketones. Org Lett 2024; 26:286-291. [PMID: 38165838 DOI: 10.1021/acs.orglett.3c03960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2024]
Abstract
Chromium-catalyzed cross-coupling of methyl ketones with cyclic ketones to β-branched β,γ-unsaturated ketones are reported. Interestingly, single-crossed aldol condensation products are formed, even in reactions in which a mixture of products is possible. The reaction is highly chemoselective and regioselective. This catalytic route gives a unique opportunity to integrate the chemistry of the synthetic challenge cross-coupling reaction of ketones and the alkene migration reaction into a reaction pot.
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Affiliation(s)
- Priyanka Adhikari
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati-781039, Assam, India
| | - Nitumoni Hazarika
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati-781039, Assam, India
| | | | - Animesh Das
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati-781039, Assam, India
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3
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Su X, Wang Y, Feng Q, Sun J. Heterodifunctionalization of Electron-Rich Alkynes Catalyzed by in Situ Generated Silylium Ions. Org Lett 2024; 26:421-426. [PMID: 38166166 DOI: 10.1021/acs.orglett.3c04208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2024]
Abstract
Silylium ions are versatile Lewis acids in organic synthesis. While they have been well-known for the activation of σ donors, catalysis initiated by the activation of π donors remains underdeveloped, particularly for alkynes. Herein, we demonstrate an example of silylium-catalyzed alkyne heterodifunctionalization. The silylium ion generated in situ from HNTf2 and the silyl reagent serve as superior catalysts in the efficient silylphosphination and silylcyanation of electron-rich alkynes with excellent regio- and stereoselectivity. The compatibility of this protocol with strongly coordinating ligands (Ph2P and CN) not only complements the metal-catalyzed systems but also expands the scope of silylium-catalyzed reactions.
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Affiliation(s)
- Xiang Su
- School of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou 510006, China
| | - Yong Wang
- Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong Special Administrative Region, China
| | - Qiang Feng
- Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong Special Administrative Region, China
| | - Jianwei Sun
- Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong Special Administrative Region, China
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4
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Zhu X, Duan J, Chen J, Liu R, Qin Z, Chen H, Yue W. Aldol Condensation for the Construction of Organic Functional Materials. Angew Chem Int Ed Engl 2024; 63:e202311879. [PMID: 37711068 DOI: 10.1002/anie.202311879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 09/10/2023] [Accepted: 09/14/2023] [Indexed: 09/16/2023]
Abstract
Aldol condensation is a cost-effective and sustainable synthetic method, offering the advantages of low complexity, substrate universality, and high efficiency. Over the past decade, it has become popular for creating next-generation organic functional materials, particularly rigid-rod conjugated (semi)conductors. This review focuses on conjugated small molecules, oligomers, and polymeric (semi)conductors synthesized through aldol condensation, with emphasis on their remarkable features in advancing n-type organic field-effect transistors (OFETs), organic electrochemical transistors (OECTs), organic photovoltaics (OPVs), and organic thermoelectrics (OTEs) as well as NIR-II photothermal conversion. Coherence character, optical properties, microstructure, and chain conformation are investigated to understand material-property relationships. Future applications and challenges in this area are also discussed.
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Affiliation(s)
- Xiuyuan Zhu
- State Key Laboratory of Optoelectronic Materials and Technologies, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices, School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou, 510275, P. R. China
| | - Jiayao Duan
- State Key Laboratory of Optoelectronic Materials and Technologies, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices, School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou, 510275, P. R. China
| | - Junxin Chen
- State Key Laboratory of Optoelectronic Materials and Technologies, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices, School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou, 510275, P. R. China
| | - Riping Liu
- State Key Laboratory of Optoelectronic Materials and Technologies, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices, School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou, 510275, P. R. China
| | - Ze Qin
- Dongguan Key Laboratory of Interdisciplinary Science for Advanced Materials and Large-Scale Scientific Facilities, School of Physical Sciences, Great Bay University, Dongguan, 523000, P. R. China
- Great Bay Institute for Advanced Study, Dongguan, 523000, P. R. China
| | - Hu Chen
- Dongguan Key Laboratory of Interdisciplinary Science for Advanced Materials and Large-Scale Scientific Facilities, School of Physical Sciences, Great Bay University, Dongguan, 523000, P. R. China
- Great Bay Institute for Advanced Study, Dongguan, 523000, P. R. China
| | - Wan Yue
- State Key Laboratory of Optoelectronic Materials and Technologies, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices, School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou, 510275, P. R. China
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5
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Adhikari P, Bhattacharyya D, Deori K, Sarmah BK, Das A. Chemo- and Regioselective Catalytic Cross-Coupling Reaction of Ketones for the Synthesis of β, γ-Disubstituted β, γ-Unsaturated Ketones. Chemistry 2023:e202303206. [PMID: 38140820 DOI: 10.1002/chem.202303206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 12/09/2023] [Accepted: 12/21/2023] [Indexed: 12/24/2023]
Abstract
C-C bond forming reaction of ketone with aldehyde is well-studied for the synthesis of α, β-unsaturated ketones, however, the reaction with two different ketones to unsaturated carbonyl compound has not yet been systematically studied. Probably due to the relatively low reactivity of ketones as electrophiles (aldol acceptors), its propensity for retro-aldol reaction. The reactions often suffer from unsatisfactory chemoselectivity (self- vs. crossed aldol products) and regioselectivity (thermodynamic vs. kinetic enolate). In this quest, we report here for the first time selective cross-coupling reaction of ketones to β-branched β, γ-unsaturated ketones by using ruthenium catalysis. Interestingly, single crossed aldol condensation products are formed even in reactions where a mixture of products is possible. Reaction is highly chemoselective, regioselective and produces H2 O as the only byproducts making the protocol environmentally benign. Method is compatible with a wide variety of sensitive functional group and applicable for even problematic aliphatic ketones as substrates. Notably, acetone was found as a three-carbon feedstock for the syntheses of simple β, γ-unsaturated ketone compounds. The process can further be extended to the gram-scale reaction and late-stage functionalization of natural products. With the help of DFT calculations, several control experiments, and deuterium-labeling experiments, the mechanistic finding demonstrated that initial aldol-condensation of ketones to a β, β-disubstituted α, β-unsaturated ketone, which further isomerizes to a β, γ- unsaturated ketone via η3 -allyl ruthenium complex.
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Affiliation(s)
- Priyanka Adhikari
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, Assam, India, 781039
| | - Dipanjan Bhattacharyya
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, Assam, India, 781039
| | - Kritartha Deori
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, Assam, India, 781039
| | - Bikash Kumar Sarmah
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, Assam, India, 781039
- Department of Chemistry, Sonari College, Assam, India
| | - Animesh Das
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, Assam, India, 781039
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6
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Christin O, Roulland E. Advancements in Enacyloxins Total Synthesis: Access to the Chlorinated Polyunsaturated Chain Peculiar to this Promising Family of Antibiotics. Org Lett 2023; 25:6869-6874. [PMID: 37676860 DOI: 10.1021/acs.orglett.3c02477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/09/2023]
Abstract
The first synthesis of the protected chain specific to the enacyloxin antibiotic family is reported. The noticeable features are (a) the construction of the chlorinated undecapentaenoic moiety implementing the sequence Tsuji's alkyne syn allyl-chlorination, E-selective Pd/Cu-catalyzed allene-alkyne coupling, Horner-Wadsworth-Emmons olefination, dehydration; (b) control of the C18 chlorinated stereogenic center by organo-catalyzed aldehyde α-chlorination; and (c) the assemblage of this aldehyde with the C1-C16 ketone using a highly diastereoselective Mukaiyama aldol.
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Affiliation(s)
- Orane Christin
- CiTCoM, UMR 8038, CNRS-Université Paris Cité, Faculté de Pharmacie, 4, avenue de l'Observatoire, 75006 Paris, France
| | - Emmanuel Roulland
- CiTCoM, UMR 8038, CNRS-Université Paris Cité, Faculté de Pharmacie, 4, avenue de l'Observatoire, 75006 Paris, France
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7
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Yuan T, Radefeld K, Shan C, Wegner C, Nichols E, Ye X, Tang Q, Wojtas L, Shi X. Asymmetric Hydrative Aldol Reaction (HAR) via Vinyl-Gold Promoted Intermolecular Ynamide Addition to Aldehydes. Angew Chem Int Ed Engl 2023; 62:e202305810. [PMID: 37276357 PMCID: PMC10527335 DOI: 10.1002/anie.202305810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 06/03/2023] [Accepted: 06/05/2023] [Indexed: 06/07/2023]
Abstract
Herein, we reported an intermolecular asymmetric hydrative aldol reaction through vinyl-gold intermediate under ambient conditions. This tandem alkyne hydration and sequential nucleophilic addition afforded a "base-free" approach to β-hydroxy amides with high efficiency (up to 95 % yields, >50 examples). Vinyl gold intermediate was applied as reactive nucleophile and Fe(acac)3 was used as the critical co-catalyst to prevent undesired protodeauration, allowing this transformation to proceed under mild conditions with good functional group tolerance and excellent stereoselectivity (>20 : 1 d.r. and up to 99 % ee).
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Affiliation(s)
- Teng Yuan
- Department of Chemistry, University of South Florida, FL 33620, Tampa, USA
| | - Kelton Radefeld
- Department of Chemistry, University of South Florida, FL 33620, Tampa, USA
| | - Chuan Shan
- Department of Chemistry, University of South Florida, FL 33620, Tampa, USA
| | - Carter Wegner
- Department of Chemistry, University of South Florida, FL 33620, Tampa, USA
| | - Erin Nichols
- Department of Chemistry, University of South Florida, FL 33620, Tampa, USA
| | - Xiaohan Ye
- Department of Chemistry, University of South Florida, FL 33620, Tampa, USA
| | - Qi Tang
- Department of Chemistry, University of South Florida, FL 33620, Tampa, USA
| | - Lukasz Wojtas
- Department of Chemistry, University of South Florida, FL 33620, Tampa, USA
| | - Xiaodong Shi
- Department of Chemistry, University of South Florida, FL 33620, Tampa, USA
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8
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Todtz SR, Schneider CW, Malakar T, Anderson C, Koska H, Zimmerman PM, Devery JJ. Controlling Catalyst Behavior in Lewis Acid-Catalyzed Carbonyl-Olefin Metathesis. J Am Chem Soc 2023; 145:13069-13080. [PMID: 37279356 PMCID: PMC10517625 DOI: 10.1021/jacs.3c01508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Lewis acid-catalyzed carbonyl-olefin metathesis has introduced a new means for revealing the behavior of Lewis acids. In particular, this reaction has led to the observation of new solution behaviors for FeCl3 that may qualitatively change how we think of Lewis acid activation. For example, catalytic metathesis reactions operate in the presence of superstoichiometric amounts of carbonyl, resulting in the formation of highly ligated (octahedral) iron geometries. These structures display reduced activity, decreasing catalyst turnover. As a result, it is necessary to steer the Fe-center away from inhibiting pathways to improve the reaction efficiency and augment yields for recalcitrant substrates. Herein, we examine the impact of the addition of TMSCl to FeCl3-catalyzed carbonyl-olefin metathesis, specifically for substrates that are prone to byproduct inhibition. Through kinetic, spectroscopic, and colligative experiments, significant deviations from the baseline metathesis reactivity are observed, including mitigation of byproduct inhibition as well as an increase in the reaction rate. Quantum chemical simulations are used to explain how TMSCl induces a change in catalyst structure that leads to these kinetic differences. Collectively, these data are consistent with the formation of a silylium catalyst, which induces the reaction through carbonyl binding. The FeCl3 activation of Si-Cl bonds to give the silylium active species is expected to have significant utility in enacting carbonyl-based transformations.
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Affiliation(s)
- Sophi R Todtz
- Department of Chemistry & Biochemistry, Loyola University Chicago, Flanner Hall, 1068 W Sheridan Road, Chicago, Illinois 60660, United States
| | - Cory W Schneider
- Department of Chemistry & Biochemistry, Loyola University Chicago, Flanner Hall, 1068 W Sheridan Road, Chicago, Illinois 60660, United States
| | - Tanmay Malakar
- Department of Chemistry, Barasat College, 10 K.N.C. Road, Barasat, Kolkata 700124, West Bengal, India
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Clare Anderson
- Department of Chemistry & Biochemistry, Loyola University Chicago, Flanner Hall, 1068 W Sheridan Road, Chicago, Illinois 60660, United States
| | - Heather Koska
- Department of Chemistry & Biochemistry, Loyola University Chicago, Flanner Hall, 1068 W Sheridan Road, Chicago, Illinois 60660, United States
| | - Paul M Zimmerman
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - James J Devery
- Department of Chemistry & Biochemistry, Loyola University Chicago, Flanner Hall, 1068 W Sheridan Road, Chicago, Illinois 60660, United States
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9
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Wu A, Yamamoto H. Super silyl-based stable protecting groups for both the C- and N-terminals of peptides: applied as effective hydrophobic tags in liquid-phase peptide synthesis. Chem Sci 2023; 14:5051-5061. [PMID: 37206381 PMCID: PMC10189889 DOI: 10.1039/d3sc01239e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 04/14/2023] [Indexed: 05/21/2023] Open
Abstract
Tag-assisted liquid-phase peptide synthesis (LPPS) is one of the important processes in peptide synthesis in pharmaceutical discovery. Simple silyl groups have positive effects when incorporated in the tags due to their hydrophobic properties. Super silyl groups contain several simple silyl groups and play an important role in modern aldol reactions. In view of the unique structural architecture and hydrophobic properties of the super silyl groups, herein, two new types of stable super silyl-based groups (tris(trihexylsilyl)silyl group and propargyl super silyl group) were developed as hydrophobic tags to increase the solubility in organic solvents and the reactivity of peptides during LPPS. The tris(trihexylsilyl)silyl group can be installed at the C-terminal of the peptides in ester form and N-terminal in carbamate form for peptide synthesis and it is compatible with hydrogenation conditions (Cbz chemistry) and Fmoc-deprotection conditions (Fmoc chemistry). The propargyl super silyl group is acid-resistant, which is compatible with Boc chemistry. Both tags are complementary to each other. The preparation of these tags requires less steps than previously reported tags. Nelipepimut-S was synthesized successfully with different strategies using these two types of super silyl tags.
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Affiliation(s)
- An Wu
- Peptide Research Centre, Chubu University 1200 Matsumoto-cho Kasugai Aichi 487-8501 Japan
| | - Hisashi Yamamoto
- Peptide Research Centre, Chubu University 1200 Matsumoto-cho Kasugai Aichi 487-8501 Japan
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10
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Kremsmair A, Sunagatullina AS, Bole LJ, Mastropierro P, Graßl S, Wilke HR, Godineau E, Hevia E, Knochel P. Exploiting Coordination Effects for the Regioselective Zincation of Diazines Using TMPZnX⋅LiX (X=Cl, Br). Angew Chem Int Ed Engl 2022; 61:e202210491. [PMID: 35943036 PMCID: PMC9826189 DOI: 10.1002/anie.202210491] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Indexed: 01/11/2023]
Abstract
A new method for regioselective zincations of challenging N-heterocyclic substrates such as pyrimidines and pyridazine was reported using bimetallic bases TMPZnX⋅LiX (TMP=2,2,6,6-tetramethylpiperidyl; X=Cl, Br). Reactions occurred under mild conditions (25-70 °C, using 1.75 equivalents of base without additives), furnishing 2-zincated pyrimidines and 3-zincated pyridazine, which were then trapped with a variety of electrophiles. Contrasting with other s-block metalating systems, which lack selectivity in their reactions even when operating at low temperatures, these mixed Li/Zn bases enabled unprecedented regioselectivities that cannot be replicated by either LiTMP nor Zn(TMP)2 on their own. Spectroscopic and structural interrogations of organometallic intermediates involved in these reactions have shed light on the complex constitution of reaction mixtures and the origins of their special reactivities.
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Affiliation(s)
- Alexander Kremsmair
- Department Chemie & BiochemieLudwig Maximilians-Universität MünchenButenandtstrasse 5–13, Haus F81377MünchenGermany
| | - Alisa S. Sunagatullina
- Department Chemie & BiochemieLudwig Maximilians-Universität MünchenButenandtstrasse 5–13, Haus F81377MünchenGermany
| | - Leonie J. Bole
- Department für Chemie und BiochemieUniversität BernFreiestrasse 33012BernSwitzerland
| | - Pasquale Mastropierro
- Department für Chemie und BiochemieUniversität BernFreiestrasse 33012BernSwitzerland
| | - Simon Graßl
- Department Chemie & BiochemieLudwig Maximilians-Universität MünchenButenandtstrasse 5–13, Haus F81377MünchenGermany
| | - Henrik R. Wilke
- Department Chemie & BiochemieLudwig Maximilians-Universität MünchenButenandtstrasse 5–13, Haus F81377MünchenGermany
| | - Edouard Godineau
- Forschung & Entwicklung SteinSyngenta Crop Protection AGSchaffhauserstrasse 1014332SteinSwitzerland
| | - Eva Hevia
- Department für Chemie und BiochemieUniversität BernFreiestrasse 33012BernSwitzerland
| | - Paul Knochel
- Department Chemie & BiochemieLudwig Maximilians-Universität MünchenButenandtstrasse 5–13, Haus F81377MünchenGermany
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11
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Kremsmair A, Sunagatullina AS, Bole LJ, Mastropierro P, Graßl S, Wilke HR, Godineau E, Hevia E, Knochel P. Exploiting Coordination Effects for the Regioselective Zincation of Diazines Using TMPZnX·LiX (X = Cl, Br). Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202210491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
| | | | - Leonie J. Bole
- Universität Bern: Universitat Bern Department für Chemie und Biochemie SWITZERLAND
| | | | - Simon Graßl
- Ludwig-Maximilians-Universitat Munchen Department of Chemistry GERMANY
| | - Henrik R. Wilke
- Ludwig-Maximilians-Universitat Munchen Department of Chemistry GERMANY
| | - Edouard Godineau
- Syngenta Crop Protection AG Forschung & Entwicklung Stein SWITZERLAND
| | - Eva Hevia
- Universität Bern: Universitat Bern Chemie und Biochemie SWITZERLAND
| | - Paul Knochel
- Ludwig-Maximilians-Universitat Munchen Department of Chemistry Butenandtstr. 5-13 81377 München GERMANY
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12
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Hayashi Y. Diarylprolinol as an Effective Organocatalyst in Asymmetric Cross-aldol Reactions of Two Different Aldehydes. CHEM REC 2022:e202200159. [PMID: 35896950 DOI: 10.1002/tcr.202200159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/06/2022] [Accepted: 07/07/2022] [Indexed: 11/10/2022]
Abstract
The aldol reaction is one of the most important carbon-carbon bond-forming reactions in organic chemistry. Asymmetric direct cross-aldol reaction of two different aldehydes has been regarded as a difficult reaction because of the side reactions such as self-aldol reaction and over reaction. We found that trifluoromethyl-substituted diarylprolinol, α,α-bis[3,5-bis(trifluoromethyl)phenyl]-2-pyrrolidinemethanol (1), is an effective organocatalyst that promotes several cross-aldol reactions of aldehydes with excellent diastereo- and enantioselectivities. Acetaldehyde can be employed as a suitable nucleophilic aldehyde. Successful electrophilic aldehydes are ethyl glyoxylate, chloroacetaldehyde, dichloroacetaldehyde, chloral, α-alkyl-α-oxo aldehyde, trifluoroacetaldehyde, glyoxal, alkenyl aldehyde, alkynyl aldehyde, and formaldehyde. Some of the aldehydes are commercially available as a polymer solution, an aqueous solution, or in the hydrated form. They can be used directly in the asymmetric aldol reaction as a commercially available form, which is a synthetic advantage. Given that the obtained aldol products possess several functional groups along with a formyl moiety, they are synthetically useful chiral building blocks.
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Affiliation(s)
- Yujiro Hayashi
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki Aza-Aoba, Aoba-ku, Sendai, Miyagi, 980-8578, Japan
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13
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Fiorito D, Keskin S, Bateman JM, George M, Noble A, Aggarwal VK. Stereocontrolled Total Synthesis of Bastimolide B Using Iterative Homologation of Boronic Esters. J Am Chem Soc 2022; 144:7995-8001. [PMID: 35499478 PMCID: PMC9100475 DOI: 10.1021/jacs.2c03192] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Bastimolide B is
a polyhydroxy macrolide isolated from marine cyanobacteria
displaying antimalarial activity. It features a dense array of hydroxylated
stereogenic centers with 1,5-relationships along a hydrocarbon chain.
These 1,5-polyols represent a particularly challenging motif for synthesis,
as the remote position of the stereocenters hampers stereocontrol.
Herein, we present a strategy for 1,5-polyol stereocontrolled synthesis
based on iterative boronic ester homologation with enantiopure magnesium
carbenoids. By merging boronic ester homologation and transition-metal-catalyzed
alkene hydroboration and diboration, the acyclic backbone of bastimolide
B was rapidly assembled from readily available building blocks with
full control over the remote stereocenters, enabling the total synthesis
to be completed in 16 steps (LLS).
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Affiliation(s)
- Daniele Fiorito
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
| | - Selbi Keskin
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
| | - Joseph M Bateman
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
| | - Malcolm George
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
| | - Adam Noble
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
| | - Varinder K Aggarwal
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, U.K
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14
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Tang L, Zang Y, Guo W, Han Z, Huang H, Sun J. Reductive Opening of Oxetanes Catalyzed by Frustrated Lewis Pairs: Unexpected Aryl Migration via Neighboring Group Participation. Org Lett 2022; 24:3259-3264. [PMID: 35467358 DOI: 10.1021/acs.orglett.2c01088] [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
B(C6F5)3 was found to catalyze an unusual double reduction of oxetanes by hydrosilane with aryl migration via neighboring group participation. Control experiments suggested that the phenonium ion serves as the key intermediate. Minor modification of this protocol also led to simple hydrosilylative opening of oxetanes.
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Affiliation(s)
- Luning Tang
- Jiangsu Key Laboratory of Advanced Catalytic Materials & Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China
| | - Yu Zang
- Jiangsu Key Laboratory of Advanced Catalytic Materials & Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China
| | - Wengang Guo
- Jiangsu Key Laboratory of Advanced Catalytic Materials & Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China
| | - Zhengyu Han
- Jiangsu Key Laboratory of Advanced Catalytic Materials & Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China
| | - Hai Huang
- Jiangsu Key Laboratory of Advanced Catalytic Materials & Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China
| | - Jianwei Sun
- Jiangsu Key Laboratory of Advanced Catalytic Materials & Technology, School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China.,Department of Chemistry and the Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration & Reconstruction, The Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong SAR 999077, China.,Shenzhen Research Institute, HKUST, No. 9 Yuexing First Road, Shenzhen 518057, China
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15
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Zong X, Liu S, Zhang Z, Ji L, Zhang T, Jia Z, Loh TP. Fluoride Anion Catalyzed Mukaiyama-Aldol Reaction: Rapid Access to α-Fluoro-β-hydroxy Esters. J Org Chem 2022; 87:6918-6926. [PMID: 35443775 DOI: 10.1021/acs.joc.2c00240] [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
The Mukaiyama-aldol reaction is probably one of the most efficient strategies to prepare synthetically useful β-hydroxy carbonyl compounds. However, only several reported methods were concerned with the accesses to α-fluoro-β-hydroxy esters. Herein, we report a protocol for a fluoride anion-mediated Mukaiyama aldol reaction with low catalytic loading in a short reaction time to incorporate fluorine at the α position into β-hydroxy esters. The method shows good functional-group tolerance and scale-up potential, moreover, is applicable to the late-stage modification of natural products and small molecular drugs.
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Affiliation(s)
- Xinlong Zong
- Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing, 211816, China
| | - Shuanglei Liu
- Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing, 211816, China
| | - Zhenguo Zhang
- Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing, 211816, China
| | - Liang Ji
- Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing, 211816, China
| | - Ting Zhang
- Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing, 211816, China
| | - Zhenhua Jia
- Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing, 211816, China
| | - Teck-Peng Loh
- Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing, 211816, China
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16
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Prasitwatcharakorn W, Rujirasereesakul C, Luanphaisarnnont T. Synthesis of 4-Aryl-1,2-Naphthoquinones via a Conjugate Addition-Oxidation Reaction Catalyzed by p-Toluenesulfonic Acid. RESULTS IN CHEMISTRY 2022. [DOI: 10.1016/j.rechem.2022.100319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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17
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Li J, Zhao P, Li R, Yang W, Zhao W. Rhodium-Catalyzed β-Dehydroborylation of Silyl Enol Ethers: Access to Highly Functionalized Enolates. Org Lett 2021; 23:9580-9585. [PMID: 34860021 DOI: 10.1021/acs.orglett.1c03796] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
An efficient rhodium-catalyzed β-dehydroborylation of aldehyde-derived silyl enol ethers (SEEs) with bis(pinacolato)diboron (B2pin2) is disclosed. The borylation reactions proceeded well with alkyl- and aryl-substituted SEEs, affording a wide array of valuable functionalized β-boryl silyl enolates with high efficiency and excellent stereoselectivity. Moreover, the borylated products, through versatile carbon-boron bond transformations, were readily converted into diverse synthetically useful molecules, including α-hydroxy ketones, functionalized SEEs, and gem-difunctionalized aldehydes.
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Affiliation(s)
- Jie Li
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Advanced Catalytic Engineering Research Center of the Ministry of Education, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, P. R. China
| | - Pei Zhao
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Advanced Catalytic Engineering Research Center of the Ministry of Education, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, P. R. China
| | - Ruoling Li
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Advanced Catalytic Engineering Research Center of the Ministry of Education, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, P. R. China
| | - Wen Yang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Advanced Catalytic Engineering Research Center of the Ministry of Education, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, P. R. China
| | - Wanxiang Zhao
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Advanced Catalytic Engineering Research Center of the Ministry of Education, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, P. R. China
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18
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Amatov T, Tsuji N, Maji R, Schreyer L, Zhou H, Leutzsch M, List B. Confinement-Controlled, Either syn- or anti-Selective Catalytic Asymmetric Mukaiyama Aldolizations of Propionaldehyde Enolsilanes. J Am Chem Soc 2021; 143:14475-14481. [PMID: 34436899 PMCID: PMC8447262 DOI: 10.1021/jacs.1c07447] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
![]()
Protected aldols
(i.e., true aldols derived from aldehydes) with
either syn- or anti- stereochemistry
are versatile intermediates in many oligopropionate syntheses. Traditional
stereoselective approaches to such aldols typically require several
nonstrategic operations. Here we report two highly enantioselective
and diastereoselective catalytic Mukaiyama aldol reactions of the
TBS- or TES- enolsilanes of propionaldehyde with aromatic aldehydes.
Our reactions directly deliver valuable silyl protected propionaldehyde
aldols in a catalyst controlled manner, either as syn- or anti- isomer. We have identified a privileged
IDPi catalyst motif that is tailored for controlling these aldolizations
with exceptional selectivities. We demonstrate how a single atom modification
in the inner core of the IDPi catalyst, replacing a CF3-group with a CF2H-group, leads to a dramatic switch in
enantiofacial differentiation of the aldehyde. The origin of this
remarkable effect was attributed to tightening of the catalytic cavity
via unconventional C–H hydrogen bonding of the CF2H group.
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Affiliation(s)
- Tynchtyk Amatov
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany
| | - Nobuya Tsuji
- Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo 001-0021, Japan
| | - Rajat Maji
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany
| | - Lucas Schreyer
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany
| | - Hui Zhou
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany
| | - Markus Leutzsch
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany
| | - Benjamin List
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany.,Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo 001-0021, Japan
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19
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Dong W, Xu X, Ma H, Lei Y, Lin Z, Zhao W. Enantioselective Rh-Catalyzed Hydroboration of Silyl Enol Ethers. J Am Chem Soc 2021; 143:10902-10909. [PMID: 34254797 DOI: 10.1021/jacs.1c06697] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The asymmetric hydroboration of alkenes has proven to be among the most powerful methods for the synthesis of chiral boron compounds. This protocol is well suitable for activated alkenes such as vinylarenes and alkenes bearing directing groups. However, the catalytic enantioselective hydroboration of O-substituted alkenes has remained unprecedented. Here we report a Rh-catalyzed enantioselective hydroboration of silyl enol ethers (SEEs) that utilizes two new chiral phosphine ligands we developed. This approach features mild reaction conditions and a broad substrate scope as well as excellent functional group tolerance, and enables highly efficient preparation of synthetically valuable chiral borylethers.
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Affiliation(s)
- Wenke Dong
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, 410082 Changsha, Hunan, P. R. China
| | - Xin Xu
- Department of Chemistry, The Hong Kong University of Science and Technology, 999077 Clear Water Bay, Kowloon, Hong Kong, P. R. China
| | - Honghui Ma
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, 410082 Changsha, Hunan, P. R. China
| | - Yaqin Lei
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, 410082 Changsha, Hunan, P. R. China
| | - Zhenyang Lin
- Department of Chemistry, The Hong Kong University of Science and Technology, 999077 Clear Water Bay, Kowloon, Hong Kong, P. R. China
| | - Wanxiang Zhao
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, 410082 Changsha, Hunan, P. R. China
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20
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Li J, Liu S, Zhong R, Yang Y, He Y, Yang J, Ma Y, Wang Z. Reversal of Regioselectivity in Nucleophilic Difluoroalkylation of α,β-Enones Employing In Situ-Formed Sterically Encumbered Silylium Catalyst. Org Lett 2021; 23:5859-5864. [PMID: 34282922 DOI: 10.1021/acs.orglett.1c01993] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
An efficient approach for the reversal of regioselectivity in the nucleophilic introduction of difluorinated carbanion into α,β-enones has been developed via a silylium catalysis. The strong electron-withdrawing properties and bulky substituents of in situ-generated silyl triflic imide catalyst is the key for the 1,4-addition reaction to proceed smoothly. The synthetic utility is highlighted by the further use of this method for the synthesis of 2,4,6-triarylsubstituted 3-fluoropyridines in a one-pot manner.
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Affiliation(s)
- Jinshan Li
- Advanced Research Institute and Department of Chemistry, Taizhou University, 1139 Shifu Avenue, Taizhou 318000, P. R. China
| | - Saimei Liu
- Advanced Research Institute and Department of Chemistry, Taizhou University, 1139 Shifu Avenue, Taizhou 318000, P. R. China
| | - Rong Zhong
- Advanced Research Institute and Department of Chemistry, Taizhou University, 1139 Shifu Avenue, Taizhou 318000, P. R. China
| | - Yaqi Yang
- Advanced Research Institute and Department of Chemistry, Taizhou University, 1139 Shifu Avenue, Taizhou 318000, P. R. China
| | - Yuru He
- Advanced Research Institute and Department of Chemistry, Taizhou University, 1139 Shifu Avenue, Taizhou 318000, P. R. China
| | - Jianguo Yang
- Advanced Research Institute and Department of Chemistry, Taizhou University, 1139 Shifu Avenue, Taizhou 318000, P. R. China
| | - Yongmin Ma
- Advanced Research Institute and Department of Chemistry, Taizhou University, 1139 Shifu Avenue, Taizhou 318000, P. R. China
| | - Zhiming Wang
- Advanced Research Institute and Department of Chemistry, Taizhou University, 1139 Shifu Avenue, Taizhou 318000, P. R. China
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21
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Luo J, Chenzhang P, Lan W, Li J, Qin Z, Fu B. A Highly Enantioselective Approach to Hydrocarbazole Derivatives Catalyzed by Diphenylmethylidene Bis(oxazoline)‐Ni(II) Complexes. ChemistrySelect 2021. [DOI: 10.1002/slct.202102134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jia‐yu Luo
- College of Science China Agricultural University Beijing 100193 P. R. China
| | - Peng‐fei Chenzhang
- College of Science China Agricultural University Beijing 100193 P. R. China
| | - Wenjie Lan
- College of Science China Agricultural University Beijing 100193 P. R. China
| | - Jia‐qi Li
- College of Science China Agricultural University Beijing 100193 P. R. China
| | - Zhaohai Qin
- College of Science China Agricultural University Beijing 100193 P. R. China
| | - Bin Fu
- College of Science China Agricultural University Beijing 100193 P. R. China
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22
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Probasco KC, Jennings MP. Stereoselective Halo-Succinimide Facilitated α-Halogenations of Substituted α-Trialkylsilyl-β-Substituted-α,β-Unsaturated Esters. J Org Chem 2021; 86:8945-8954. [PMID: 34161091 DOI: 10.1021/acs.joc.1c00876] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The NXS (X = Cl, Br)-mediated halogenation of a series of (E)-α-trimethylsilyl-β-alkyl(aryl)-α,β-unsaturated esters in dimethylformamide (DMF) has furnished (Z)-β-substituted-α-halogenated-α,β-unsaturated ester products in moderate to high isolated yields (58-90%) with dr values of >20:1 coupled with the inversion of olefin stereochemistry. The reaction process was hypothesized to include an initial halonium cation intermediate, followed by regioselective ring opening with DMF. Subsequent anti-E2-type concomitant elimination allowed for the stereoselective formation of the product vinylic bromo-and chloroesters.
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Affiliation(s)
- Kristina C Probasco
- Department of Chemistry and Biochemistry, The University of Alabama, 250 Hackberry Lane, Tuscaloosa, Alabama 35487-0336, United States
| | - Michael P Jennings
- Department of Chemistry and Biochemistry, The University of Alabama, 250 Hackberry Lane, Tuscaloosa, Alabama 35487-0336, United States
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23
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Wang PY, Massad I, Marek I. Stereoselective Sc(OTf) 3 -Catalyzed Aldol Reactions of Disubstituted Silyl Enol Ethers of Aldehydes with Acetals. Angew Chem Int Ed Engl 2021; 60:12765-12769. [PMID: 33779017 DOI: 10.1002/anie.202101634] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 03/25/2021] [Indexed: 12/14/2022]
Abstract
Facile and modular access to stereodefined disubstituted aldehyde-derived silyl enol ethers allowed their successful application in a stereoselective aldol reaction affording the products with excellent yields and diastereomeric ratios. The counter-intuitive stereochemical behavior of this Mukaiyama-aldol reaction is accounted for by a non-classical open transition state.
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Affiliation(s)
- Peter-Yong Wang
- Schulich Faculty of Chemistry, Technion-, Israel Institute of Technology, Technion City, Haifa, 3200009, Israel
| | - Itai Massad
- Schulich Faculty of Chemistry, Technion-, Israel Institute of Technology, Technion City, Haifa, 3200009, Israel
| | - Ilan Marek
- Schulich Faculty of Chemistry, Technion-, Israel Institute of Technology, Technion City, Haifa, 3200009, Israel
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24
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Wang P, Massad I, Marek I. Stereoselective Sc(OTf)
3
‐Catalyzed Aldol Reactions of Disubstituted Silyl Enol Ethers of Aldehydes with Acetals. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202101634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Peter‐Yong Wang
- Schulich Faculty of Chemistry, Technion— Israel Institute of Technology Technion City Haifa 3200009 Israel
| | - Itai Massad
- Schulich Faculty of Chemistry, Technion— Israel Institute of Technology Technion City Haifa 3200009 Israel
| | - Ilan Marek
- Schulich Faculty of Chemistry, Technion— Israel Institute of Technology Technion City Haifa 3200009 Israel
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25
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Juaristi E. Recent developments in next generation (S)-proline-derived chiral organocatalysts. Tetrahedron 2021. [DOI: 10.1016/j.tet.2021.132143] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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26
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Abstract
![]()
Practical, efficient,
and general methods for the diversification
of N-heterocycles have been a recurrent goal in chemical
synthesis due to the ubiquitous influence of these motifs within bioactive
frameworks. Here, we describe a direct, catalytic, and selective functionalization
of azines via silylium activation. Our catalyst design enables mild
conditions and a remarkable functional group tolerance in a one-pot
setup.
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Affiliation(s)
- Carla Obradors
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr, 45470, Germany
| | - Benjamin List
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, Mülheim an der Ruhr, 45470, Germany
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27
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Malakar T, Hanson CS, Devery JJ, Zimmerman PM. Combined Theoretical and Experimental Investigation of Lewis Acid-Carbonyl Interactions for Metathesis. ACS Catal 2021; 11:4381-4394. [PMID: 34017648 DOI: 10.1021/acscatal.0c05277] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The coordination of a carbonyl to a Lewis acid represents the first step in a wide range of catalytic transformations. In many reactions it is necessary for the Lewis acid to discriminate between starting material and product, and as a result, how these structures behave in solution must be characterized. Herein, we report the application of computational modeling to calculate properties of the solution interactions of acetone and benzaldehyde with FeCl3. Using these chemical models, we can predict spectral features in the carbonyl region of infrared (IR) spectroscopy. These simulated spectra are then directly compared to experimental spectra generated via titration-IR. We observe good agreement between theory and experiment, in that, between 0 and 1 equiv carbonyl with respect to FeCl3, a pairwise interaction dominates the spectra. When >1 equiv carbonyl is present, our theoretical model predicts two possible structures composed of 4:1 carbonyl to FeCl3, for acetone as well as benzaldehyde. When these predicted spectra are compared with titration-IR data, both structures contribute to the observed solution interactions. These findings suggest that the resting state of FeCl3-catalyzed carbonyl-based reactions employing simple substrates starts as a Lewis pair, but this structure is gradually consumed and becomes a highly ligated, catalytically less active Fe-centered complex as the reaction proceeds. An analytical model is proposed to quantify catalyst inhibition due to equilibrium between 1:1 and 4:1 carbonyl:Fe complexes.
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Affiliation(s)
- Tanmay Malakar
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Carly S. Hanson
- Department of Chemistry & Biochemistry, Loyola University Chicago, Flanner Hall, 1068 West Sheridan Road, Chicago, Illinois 60660, United States
| | - James J. Devery
- Department of Chemistry & Biochemistry, Loyola University Chicago, Flanner Hall, 1068 West Sheridan Road, Chicago, Illinois 60660, United States
| | - Paul M. Zimmerman
- Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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28
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Klare HFT, Albers L, Süsse L, Keess S, Müller T, Oestreich M. Silylium Ions: From Elusive Reactive Intermediates to Potent Catalysts. Chem Rev 2021; 121:5889-5985. [PMID: 33861564 DOI: 10.1021/acs.chemrev.0c00855] [Citation(s) in RCA: 97] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The history of silyl cations has all the makings of a drama but with a happy ending. Being considered reactive intermediates impossible to isolate in the condensed phase for decades, their actual characterization in solution and later in solid state did only fuel the discussion about their existence and initially created a lot of controversy. This perception has completely changed today, and silyl cations and their donor-stabilized congeners are now widely accepted compounds with promising use in synthetic chemistry. This review provides a comprehensive summary of the fundamental facts and principles of the chemistry of silyl cations, including reliable ways of their preparation as well as their physical and chemical properties. The striking features of silyl cations are their enormous electrophilicity and as such reactivity as super Lewis acids as well as fluorophilicity. Known applications rely on silyl cations as reactants, stoichiometric reagents, and promoters where the reaction success is based on their steady regeneration over the course of the reaction. Silyl cations can even be discrete catalysts, thereby opening the next chapter of their way into the toolbox of synthetic methodology.
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Affiliation(s)
- Hendrik F T Klare
- Institut für Chemie, Technische Universität Berlin, Strasse des 17 Juni 115, 10623 Berlin, Germany
| | - Lena Albers
- Institut für Chemie, Carl von Ossietzky Universität Oldenburg, Carl von Ossietzky-Strasse 9-11, 26129 Oldenburg, Germany
| | - Lars Süsse
- Institut für Chemie, Technische Universität Berlin, Strasse des 17 Juni 115, 10623 Berlin, Germany
| | - Sebastian Keess
- Institut für Chemie, Technische Universität Berlin, Strasse des 17 Juni 115, 10623 Berlin, Germany
| | - Thomas Müller
- Institut für Chemie, Carl von Ossietzky Universität Oldenburg, Carl von Ossietzky-Strasse 9-11, 26129 Oldenburg, Germany
| | - Martin Oestreich
- Institut für Chemie, Technische Universität Berlin, Strasse des 17 Juni 115, 10623 Berlin, Germany
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29
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Huang H, Zhang T, Sun J. Mild C–C Bond Formation via Lewis Acid Catalyzed Oxetane Ring Opening with Soft Carbon Nucleophiles. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202013062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Hai Huang
- Jiangsu Key Laboratory of Advanced Catalytic Materials & Technology School of Petrochemical Engineering Changzhou University Changzhou China
| | - Tianyu Zhang
- Jiangsu Key Laboratory of Advanced Catalytic Materials & Technology School of Petrochemical Engineering Changzhou University Changzhou China
| | - Jianwei Sun
- Jiangsu Key Laboratory of Advanced Catalytic Materials & Technology School of Petrochemical Engineering Changzhou University Changzhou China
- Department of Chemistry The Hong Kong University of Science and Technology, Clear Water Bay Kowloon, Hong Kong SAR China
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30
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Huang H, Zhang T, Sun J. Mild C-C Bond Formation via Lewis Acid Catalyzed Oxetane Ring Opening with Soft Carbon Nucleophiles. Angew Chem Int Ed Engl 2021; 60:2668-2673. [PMID: 33459485 DOI: 10.1002/anie.202013062] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Indexed: 11/09/2022]
Abstract
Mild oxetane opening by soft carbon nucleophiles has been developed for efficient C-C bond formation. In the presence of LiNTf2 or TBSNTf2 as catalyst, silyl ketene acetals were found to be effective nucleophiles to generate a wide range of highly oxygenated molecules, which are key substructure in natural products like polyketides. Furthermore, intramolecular oxetane opening by a styrene-based carbon nucleophile via a Prins-type process was also achieved with Sc(OTf)3 as catalyst, leading to efficient formation of the useful 2,3-dihydrobenzo[b]oxepine skeleton.
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Affiliation(s)
- Hai Huang
- Jiangsu Key Laboratory of Advanced Catalytic Materials & Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, China
| | - Tianyu Zhang
- Jiangsu Key Laboratory of Advanced Catalytic Materials & Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, China
| | - Jianwei Sun
- Jiangsu Key Laboratory of Advanced Catalytic Materials & Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, China.,Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
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31
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Benzene-1,3-diol derivatives as the inhibitors of butyrylcholinesterase: An emergent target of Alzheimer’s disease. JOURNAL OF THE SERBIAN CHEMICAL SOCIETY 2021. [DOI: 10.2298/jsc210416073d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Molecular docking is a powerful and significant approach for the identification of lead molecules on the basis of virtual screening. With it a large number of compounds can be tested and based on the scoring function and ranking, the conclusion can be made about how the selected compounds can inhibit the targeted protein/receptor. Considering the importance of selective inhibitors of cholinesterase in the treatment of Alzheimer disease, this research is focused on the determination of the mechanism of binding interactions of few benzene-1,3-diol derivatives within the active site of both acetyl-choline-sterase (AChE) and butyrylcholinesterase (BChE). All the selective ligands were found to have a greater binding affinity with the BChE when compared to that of AChE, by an average value of ~?28.4 and ~?12.5 kJ/mol, respectively. The results suggested that the identified inhibitors can be used as the lead com-pounds for the development of novel inhibitors of the targeted enzymes against some specific diseases, thus opening the possibility of new therapeutic strategies.
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32
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Affiliation(s)
- Shunichi Fukuzumi
- Department of Chemistry and Nano Science Ewha Womans University Seoul 03760 South Korea
- Faculty of Science and Engineering Meijo University Nagoya Aichi 468‐0073 Japan
| | - Yong‐Min Lee
- Department of Chemistry and Nano Science Ewha Womans University Seoul 03760 South Korea
- Research Institute for Basic Sciences Ewha Womans University Seoul 03760 South Korea
| | - Wonwoo Nam
- Department of Chemistry and Nano Science Ewha Womans University Seoul 03760 South Korea
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33
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Trost BM, Hung C(J, Mata G. Zweikernige Metall‐ProPhenol‐Katalysatoren: Entwicklung und Anwendungen in der Synthese. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201909692] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Barry M. Trost
- Department of ChemistryStanford University 333 Campus Drive Stanford CA 94305 USA
| | - Chao‐I (Joey) Hung
- Department of ChemistryStanford University 333 Campus Drive Stanford CA 94305 USA
| | - Guillaume Mata
- Department of ChemistryStanford University 333 Campus Drive Stanford CA 94305 USA
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34
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Li J, Qu S, Zhao W. Rhodium‐Catalyzed Remote C(sp
3
)−H Borylation of Silyl Enol Ethers. Angew Chem Int Ed Engl 2020; 59:2360-2364. [DOI: 10.1002/anie.201913281] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 11/27/2019] [Indexed: 11/10/2022]
Affiliation(s)
- Jie Li
- State Key Laboratory of Chemo/Biosensing and ChemometricsCollege of Chemistry and Chemical EngineeringHunan University Changsha Hunan 410082 P. R. China
| | - Shuanglin Qu
- State Key Laboratory of Chemo/Biosensing and ChemometricsCollege of Chemistry and Chemical EngineeringHunan University Changsha Hunan 410082 P. R. China
| | - Wanxiang Zhao
- State Key Laboratory of Chemo/Biosensing and ChemometricsCollege of Chemistry and Chemical EngineeringHunan University Changsha Hunan 410082 P. R. China
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35
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Hanson CS, Psaltakis MC, Cortes JJ, Siddiqi SS, Devery JJ. Investigation of Lewis Acid-Carbonyl Solution Interactions via Infrared-Monitored Titration. J Org Chem 2020; 85:820-832. [PMID: 31830419 DOI: 10.1021/acs.joc.9b02822] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Lewis acid-activation of carbonyl-containing substrates is broadly utilized in organic synthesis. In order to facilitate the development of novel reaction pathways and understand existing methods, it is necessary to determine the solution interactions between Lewis acids and Lewis bases. Herein, we report the application of in situ infrared spectroscopy and solution conductivity toward the identification of the solution structures formed when a range of carbonyl compounds are combined with catalytically active metal halide Lewis acids under synthetically relevant conditions. These data are consistent with formation of Lewis acid-dependent complexes, where metals of low relative Lewis acidity display no ground state interaction with carbonyls. Conversely, we observed the formation of polyligated complexes when stronger Lewis acids (SnCl4, TiCl4, ZrCl4, FeCl3, and AlCl3) were treated with ketones, aldehydes, and esters. This collection of observations is intended to assist the synthetic chemist in the design of new catalysts and the development of novel methods.
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Affiliation(s)
- Carly S Hanson
- Department of Chemistry & Biochemistry , Loyola University Chicago , Flanner Hall, 1068 W Sheridan Road , Chicago , Illinois 60660 , United States
| | - Mary C Psaltakis
- Department of Chemistry & Biochemistry , Loyola University Chicago , Flanner Hall, 1068 W Sheridan Road , Chicago , Illinois 60660 , United States
| | - Janiel J Cortes
- Department of Chemistry & Biochemistry , Loyola University Chicago , Flanner Hall, 1068 W Sheridan Road , Chicago , Illinois 60660 , United States
| | - Sameera S Siddiqi
- Department of Chemistry & Biochemistry , Loyola University Chicago , Flanner Hall, 1068 W Sheridan Road , Chicago , Illinois 60660 , United States
| | - James J Devery
- Department of Chemistry & Biochemistry , Loyola University Chicago , Flanner Hall, 1068 W Sheridan Road , Chicago , Illinois 60660 , United States
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36
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Arata S, Suzuki K, Yamaguchi K, Sunada Y. Supersilyl as an effective monodentate ligand to stabilize four-coordinate manganese( ii) complexes. Dalton Trans 2020; 49:17537-17541. [DOI: 10.1039/d0dt03837g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Supersilyl, –Si(SiMe3)3, serves as an effective ligand to afford a series of four-coordinate manganese(ii) complexes.
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Affiliation(s)
- Shogo Arata
- Department of Applied Chemistry
- School of Engineering
- The University of Tokyo
- Tokyo 153-8505
- Japan
| | - Kosuke Suzuki
- Department of Applied Chemistry
- School of Engineering
- The University of Tokyo
- Tokyo 113-8656
- Japan
| | - Kazuya Yamaguchi
- Department of Applied Chemistry
- School of Engineering
- The University of Tokyo
- Tokyo 113-8656
- Japan
| | - Yusuke Sunada
- Department of Applied Chemistry
- School of Engineering
- The University of Tokyo
- Tokyo 153-8505
- Japan
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37
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Li J, Qu S, Zhao W. Rhodium‐Catalyzed Remote C(sp
3
)−H Borylation of Silyl Enol Ethers. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201913281] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Jie Li
- State Key Laboratory of Chemo/Biosensing and ChemometricsCollege of Chemistry and Chemical EngineeringHunan University Changsha Hunan 410082 P. R. China
| | - Shuanglin Qu
- State Key Laboratory of Chemo/Biosensing and ChemometricsCollege of Chemistry and Chemical EngineeringHunan University Changsha Hunan 410082 P. R. China
| | - Wanxiang Zhao
- State Key Laboratory of Chemo/Biosensing and ChemometricsCollege of Chemistry and Chemical EngineeringHunan University Changsha Hunan 410082 P. R. China
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38
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Zeng R, Liu J, Ding S, Sun L, Wu L, Cao L, Qiu J. Construction of Class I Aldolases-like Carboxyl-Controlled-Graphene Oxide Supported 3-Aminopropyl-triethoxysilane Heterogeneous Catalysts for Aldol Reaction. Catal Letters 2019. [DOI: 10.1007/s10562-019-03048-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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39
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Trost BM, Hung C(J, Mata G. Dinuclear Metal‐ProPhenol Catalysts: Development and Synthetic Applications. Angew Chem Int Ed Engl 2019; 59:4240-4261. [DOI: 10.1002/anie.201909692] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Indexed: 12/16/2022]
Affiliation(s)
- Barry M. Trost
- Department of ChemistryStanford University 333 Campus Drive Stanford CA 94305 USA
| | - Chao‐I (Joey) Hung
- Department of ChemistryStanford University 333 Campus Drive Stanford CA 94305 USA
| | - Guillaume Mata
- Department of ChemistryStanford University 333 Campus Drive Stanford CA 94305 USA
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40
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Affiliation(s)
- Lucas Schreyer
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Deutschland
| | - Roberta Properzi
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Deutschland
| | - Benjamin List
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Deutschland
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41
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Abstract
High acidity and structural confinement are pivotal elements in asymmetric acid catalysis. The recently introduced imidodiphosphorimidate (IDPi) Brønsted acids have met with remarkable success in combining those features, acting as powerful Brønsted acid catalysts and "silylium" Lewis acid precatalysts in numerous thus far inaccessible transformations. Substrates as challenging to activate as simple olefins were readily transformed, ketones were employed as acceptors in aldolizations allowing sub-ppm level catalysis, whereas enolates of the smallest donor aldehyde, acetaldehyde, did not polymerize but selectively added a single time to a variety of acceptor aldehydes.
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Affiliation(s)
- Lucas Schreyer
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Roberta Properzi
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Benjamin List
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
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42
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Han ZS, Wu H, Qu B, Wang Y, Wu L, Zhang L, Xu Y, Wu L, Zhang Y, Lee H, Roschangar F, Song JJ, Senanayake CH. New class of P-stereogenic chiral Brønsted acid catalysts derived from chiral phosphinamides. Tetrahedron Lett 2019. [DOI: 10.1016/j.tetlet.2019.06.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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43
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Yang H, Zheng WH. Parallel Kinetic Resolution of Unsymmetrical Acyclic Aliphatic syn-1,3-Diols. Org Lett 2019; 21:5197-5200. [PMID: 31247762 DOI: 10.1021/acs.orglett.9b01801] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Disclosed is a mild, reliable, and enantioselective catalytic parallel kinetic resolution of unsymmetrical acyclic aliphatic syn-1,3-diol derived acetals mediated by chiral phosphoric acid. This method provides stereoselective access to a variety of syn-1,3-diols as valuable building blocks with high enantioselectivity. Moreover, this mild system allows for site-selective protection of optically pure syn-1,3-diols in excellent regioselectivity.
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Affiliation(s)
- Hui Yang
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering , Nanjing University , 163 Xianlin Avenue , Nanjing 210023 , Jiangsu , China
| | - Wen-Hua Zheng
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering , Nanjing University , 163 Xianlin Avenue , Nanjing 210023 , Jiangsu , China
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44
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Wang X, Zhao X, Li X, Huo B, Dong Y, Liang D, Ma Y. Brønsted acid-catalyzed radical C H functionalization of acetone with N-allyl anilines to give 3-(3-oxobutyl)indolines. Tetrahedron Lett 2019. [DOI: 10.1016/j.tetlet.2019.04.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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45
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Trost BM, Hung CIJ, Gnanamani E. Tuning the Reactivity of Ketones through Unsaturation: Construction of Cyclic and Acyclic Quaternary Stereocenters via Zn-ProPhenol Catalyzed Mannich Reactions. ACS Catal 2019. [DOI: 10.1021/acscatal.8b04685] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Barry M. Trost
- Department of Chemistry, Stanford University, Stanford, California 94305-5080, United States
| | - Chao-I Joey Hung
- Department of Chemistry, Stanford University, Stanford, California 94305-5080, United States
| | - Elumalai Gnanamani
- Department of Chemistry, Stanford University, Stanford, California 94305-5080, United States
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46
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Satpathi B, Dutta L, Ramasastry SSV. Metal- and Hydride-Free Pentannulative Reductive Aldol Reaction. Org Lett 2019; 21:170-174. [PMID: 30543435 DOI: 10.1021/acs.orglett.8b03658] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Traditionally, the reductive aldol reaction is a metal-catalyzed and hydride-promoted coupling between enones and aldehydes. We present a phosphine-mediated diastereoselective intramolecular reductive aldol reaction of α-substituted dienones and aldehydes, which is metal-free and hydride-free. The synthetic utility of the reductive aldol adducts is demonstrated by elaborating them in one step to indeno[1,2- b]furanones, indeno[1,2- b]pyrans, and dibenzo[ a, h]azulen-8-ones.
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Affiliation(s)
- Bishnupada Satpathi
- Organic Synthesis and Catalysis Lab, Department of Chemical Sciences , Indian Institute of Science Education and Research (IISER) Mohali , Sector 81 , Manauli PO, S. A. S. Nagar, Punjab 140306 , India
| | - Lona Dutta
- Organic Synthesis and Catalysis Lab, Department of Chemical Sciences , Indian Institute of Science Education and Research (IISER) Mohali , Sector 81 , Manauli PO, S. A. S. Nagar, Punjab 140306 , India
| | - S S V Ramasastry
- Organic Synthesis and Catalysis Lab, Department of Chemical Sciences , Indian Institute of Science Education and Research (IISER) Mohali , Sector 81 , Manauli PO, S. A. S. Nagar, Punjab 140306 , India
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47
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Gram-scale preparation of dialkylideneacetones through Ca(OH)2-catalyzed Claisen-Schmidt condensation in dilute aqueous EtOH. CHINESE CHEM LETT 2019. [DOI: 10.1016/j.cclet.2018.01.035] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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48
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Song W, Wang JH, Wu J, Liu J, Chen XL, Liu LM. Asymmetric assembly of high-value α-functionalized organic acids using a biocatalytic chiral-group-resetting process. Nat Commun 2018; 9:3818. [PMID: 30232330 PMCID: PMC6145935 DOI: 10.1038/s41467-018-06241-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Accepted: 08/24/2018] [Indexed: 11/21/2022] Open
Abstract
The preparation of α-functionalized organic acids can be greatly simplified by adopting a protocol involving the catalytic assembly of achiral building blocks. However, the enzymatic assembly of small amino acids and aldehydes to form numerous α-functionalized organic acids is highly desired and remains a significant challenge. Herein, we report an artificially designed chiral-group-resetting biocatalytic process, which uses simple achiral glycine and aldehydes to synthesize stereodefined α-functionalized organic acids. This cascade biocatalysis comprises a basic module and three different extender modules and operates in a modular assembly manner. The engineered Escherichia coli catalysts, which contained different module(s), provide access to α-keto acids, α-hydroxy acids, and α-amino acids with excellent conversion and enantioselectivities. Therefore, this biocatalytic process provides an attractive strategy for the conversion of low-cost achiral starting materials to high-value α-functionalized organic acids. Alpha-functionalized organic acids are building blocks of many bioactive compounds. Here, the authors developed a toolbox-like, modular set of enzymes that reset chiral groups, turning achiral glycine and simple aldehydes into stereodefined α-keto acids, α-hydroxy acids, and α-amino acids.
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Affiliation(s)
- Wei Song
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Jin-Hui Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Jing Wu
- School of Pharmaceutical Sciences, Jiangnan University, Wuxi, 214122, China
| | - Jia Liu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Xiu-Lai Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Li-Ming Liu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China. .,Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China. .,National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi, 214122, China.
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49
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Bae HY, List B. Triflimide: An Overlooked High-Performance Catalyst of the Mukaiyama Aldol Reaction of Silyl Ketene Acetals with Ketones. Chemistry 2018; 24:13767-13772. [PMID: 29943495 DOI: 10.1002/chem.201803142] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Indexed: 12/20/2022]
Abstract
The Mukaiyama aldol reaction is a widely applied carbon-carbon bond forming reaction. However, despite numerous well-established methods using aldehydes as acceptors, only few examples exist with ketones. Here we report a highly practical catalytic approach to this transformation, namely, the triflimide catalyzed Mukaiyama aldol reaction of silyl ketene acetals with ketones. This method exhibits a broad substrate scope, is very rapid, tolerates functionalized substrates, and requires only parts-per-million catalyst loadings with preparative scale reactions up to hundreds of grams in excellent purity (>99 %).
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Affiliation(s)
- Han Yong Bae
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Benjamin List
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
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50
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Gulotty EM, Staples RJ, Biros SM, Gaspar PP, Rath NP, Winchester WR. Crystal structures of 2-bromo-1,1,1,3,3,3-hexa-methyl-2-(tri-methyl-sil-yl)tris-ilane and 2-bromo-1,1,1,3,3,3-hexa-isopropyl-2-(triiso-propyl-sil-yl)tri-silane. Acta Crystallogr E Crystallogr Commun 2018; 74:1142-1146. [PMID: 30116580 PMCID: PMC6072994 DOI: 10.1107/s2056989018009696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 07/06/2018] [Indexed: 11/10/2022]
Abstract
The synthesis and crystal structures of two tris-(tri-alkyl-sil-yl)silyl bromide compounds, C9H27BrSi4 (I, HypSiBr) and C27H63BrSi4 (II, TipSiBr), are described. Compound I was prepared in 85% yield by free-radical bromination of 1,1,1,3,3,3-hexa-methyl-2-(tri-methyl-sil-yl)tris-ilane using bromo-butane and 2,2'-azobis(2-methyl-propio-nitrile) as a radical initiator at 333 K. The mol-ecule possesses threefold rotational symmetry, with the central Si atom and the Br atom being located on the threefold rotation axis. The Si-Br bond distance is 2.2990 (12) Å and the Si-Si bond lengths are 2.3477 (8) Å. The Br-Si-Si bond angles are 104.83 (3)° and the Si-Si-Si bond angles are 113.69 (2)°, reflecting the steric hindrance inherent in the three tri-methyl-silyl groups attached to the central Si atom. Compound II was prepared in 55% yield by free-radical bromination of 1,1,1,3,3,3-hexa-isopropyl-2-(triiso-propyl-sil-yl)tris-ilane using N-bromo-succinimide and 2,2'-azobis(2-methyl-propio-nitrile) as a radical initiator at 353 K. Here the Si-Br bond length is 2.3185 (7) Å and the Si-Si bond lengths range from 2.443 (1) to 2.4628 (9) Å. The Br-Si-Si bond angles range from 98.44 (3) to 103.77 (3)°, indicating steric hindrance between the three triiso-propyl-silyl groups.
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Affiliation(s)
- Eva M. Gulotty
- Department of Chemistry, Grand Valley State University, 1 Campus Dr., Allendale, MI 49401, USA
| | - Richard J. Staples
- Center for Crystallographic Research, Department of Chemistry, Michigan State, University, 578 S. Shaw Lane, East Lansing, MI, USA
| | - Shannon M. Biros
- Department of Chemistry, Grand Valley State University, 1 Campus Dr., Allendale, MI 49401, USA
| | - Peter P. Gaspar
- Department of Chemistry, Washington University, St. Louis, MO 63130-4899, USA
| | - Nigam P. Rath
- Department of Chemistry, University of Missouri St. Louis, St. Louis, MO 63121-4499, USA
| | - William R. Winchester
- Department of Chemistry, Grand Valley State University, 1 Campus Dr., Allendale, MI 49401, USA
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