1
|
Wang Y, Wang Y, Du X, Zheng K, Zhai S, Bai S, Fang L, Zhang T. Catalytic Enantioselective Propargylation of Pyrazolones by Amide-Based Phase-Transfer Catalysts. Org Lett 2024. [PMID: 39185762 DOI: 10.1021/acs.orglett.4c02441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/27/2024]
Abstract
In this paper, we developed a highly enantioselective alkylation of 4-substituted pyrazolones catalyzed by phase-transfer catalysis. Cheap halohydrocarbons were employed as electrophilic alkylationg agents, and propargyl, allyl, and benzyl products with all-carbon quaternary stereocenters were afforded with excellent enantioselectivities and good yields. We found that the unique structures of the catalyst (hydrogen bond donors of the C-9 hydroxyl group and amide group, the triphenyl at the NH-position) were important for good enantioselectivity. Furthermore, chiral propargyl products could be easily connected to azide molecules by click cycloaddition, which offers unique opportunities to obtain structurally diverse chiral pyrazolones.
Collapse
Affiliation(s)
- Yakun Wang
- School of Pharmacy, Xinxiang Medical University, Xinxiang, Henan 453003, P.R. China
| | - Yingying Wang
- School of Pharmacy, Xinxiang Medical University, Xinxiang, Henan 453003, P.R. China
| | - Xiaoyu Du
- School of Pharmacy, Xinxiang Medical University, Xinxiang, Henan 453003, P.R. China
| | - Kaiting Zheng
- School of Pharmacy, Xinxiang Medical University, Xinxiang, Henan 453003, P.R. China
| | - Shuman Zhai
- School of Pharmacy, Xinxiang Medical University, Xinxiang, Henan 453003, P.R. China
| | - Suping Bai
- School of Pharmacy, Xinxiang Medical University, Xinxiang, Henan 453003, P.R. China
| | - Lizhen Fang
- School of Pharmacy, Xinxiang Medical University, Xinxiang, Henan 453003, P.R. China
| | - Tao Zhang
- School of Pharmacy, Xinxiang Medical University, Xinxiang, Henan 453003, P.R. China
| |
Collapse
|
2
|
Lu J, Huang L, Liang H, Wang Z, Kato T, Liu Y, Maruoka K. Asymmetric Phase-Transfer Alkylation of Readily Available Aryl Aldehyde Schiff Bases of Amino Acid Ethyl Esters. Org Lett 2024; 26:4163-4167. [PMID: 38289671 DOI: 10.1021/acs.orglett.3c04290] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
Asymmetric phase-transfer alkylation of the N-(arylmethylene)-α-alkylamino acid ethyl esters and N-(arylmethylene)glycine ethyl esters was found to be catalyzed by the (R)- or (S)-Simplified Maruoka Catalyst with high efficiency and excellent enantioselectivity. This approach was successfully applied to the enantioselective formal synthesis of the angiotensin II type 2 receptor (AT2R) antagonists Olodanrigan and LX9211, and the practical aspect is demonstrated by the kilogram-scale synthesis of a key intermediate for the synthesis of LX9211.
Collapse
Affiliation(s)
- Jinying Lu
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China
- Guangdong Provincial Key Laboratory of Plant Resources Biorefinery, Guangdong University of Technology, Guangzhou 510006, China
| | - Lei Huang
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China
- Guangdong Provincial Key Laboratory of Plant Resources Biorefinery, Guangdong University of Technology, Guangzhou 510006, China
| | - Huatai Liang
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China
- Guangdong Provincial Key Laboratory of Plant Resources Biorefinery, Guangdong University of Technology, Guangzhou 510006, China
| | - Zhe Wang
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China
- Guangdong Provincial Key Laboratory of Plant Resources Biorefinery, Guangdong University of Technology, Guangzhou 510006, China
| | - Terumasa Kato
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China
- Guangdong Provincial Key Laboratory of Plant Resources Biorefinery, Guangdong University of Technology, Guangzhou 510006, China
- Laboratory of Organocatalytic Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo, Kyoto 606-8501, Japan
| | - Yan Liu
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China
- Guangdong Provincial Key Laboratory of Plant Resources Biorefinery, Guangdong University of Technology, Guangzhou 510006, China
| | - Keiji Maruoka
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China
- Guangdong Provincial Key Laboratory of Plant Resources Biorefinery, Guangdong University of Technology, Guangzhou 510006, China
- Laboratory of Organocatalytic Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo, Kyoto 606-8501, Japan
| |
Collapse
|
3
|
Shen HR, Li CX, Jiang X, Lin Y, Liu JH, Zhu F, Wu ZL, Cai T, Wen W, He RX, Guo QX. Chiral aldehyde catalysis enables direct asymmetric α-substitution reaction of N-unprotected amino acids with halohydrocarbons. Chem Sci 2023; 14:5665-5671. [PMID: 37265737 PMCID: PMC10231321 DOI: 10.1039/d3sc01294h] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 05/02/2023] [Indexed: 06/03/2023] Open
Abstract
The direct catalytic α-hydrocarbylation of readily available amino acids with halohydrocarbons is one of the most straightforward methods leading to α,α-disubstituted non-proteinogenic α-amino acid compounds. However, all the reported methodologies depend on N-protected amino acids as starting materials. Herein, we report on three highly efficient aldehyde-catalyzed direct α-hydrocarbylations of N-unprotected amino acid esters with aryl-, allyl-, and benzyl halides. By promoting a simple chiral BINOL-aldehyde catalyst or combining catalysts of a chiral aldehyde and Lewis acid ZnCl2, the asymmetric α-arylation, α-allylation, and α-benzylation of amino acid esters with the corresponding halohydrocarbons proceed smoothly, producing α,α-disubstituted α-amino acids in moderate-to-high yields and good-to-excellent enantioselectivities. The asymmetric α-arylation reaction can be applied in the formal synthesis of the clinical candidate compound (+)-AG-041R. Based on the results given by control experiments, three reaction models are proposed to illustrate the stereoselective-control outcomes.
Collapse
Affiliation(s)
- Hao-Ran Shen
- Key Laboratory of Applied Chemistry of Chongqing Municipality, Chongqing Key Laboratory of Soft-Matter Material Chemistry and Function Manufacturing, School of Chemistry and Chemical Engineering, Southwest University Chongqing 400715 China
| | - Chao-Xing Li
- Key Laboratory of Applied Chemistry of Chongqing Municipality, Chongqing Key Laboratory of Soft-Matter Material Chemistry and Function Manufacturing, School of Chemistry and Chemical Engineering, Southwest University Chongqing 400715 China
| | - Xin Jiang
- Key Laboratory of Applied Chemistry of Chongqing Municipality, Chongqing Key Laboratory of Soft-Matter Material Chemistry and Function Manufacturing, School of Chemistry and Chemical Engineering, Southwest University Chongqing 400715 China
| | - Yao Lin
- Key Laboratory of Applied Chemistry of Chongqing Municipality, Chongqing Key Laboratory of Soft-Matter Material Chemistry and Function Manufacturing, School of Chemistry and Chemical Engineering, Southwest University Chongqing 400715 China
| | - Jian-Hua Liu
- Key Laboratory of Applied Chemistry of Chongqing Municipality, Chongqing Key Laboratory of Soft-Matter Material Chemistry and Function Manufacturing, School of Chemistry and Chemical Engineering, Southwest University Chongqing 400715 China
| | - Fang Zhu
- Key Laboratory of Applied Chemistry of Chongqing Municipality, Chongqing Key Laboratory of Soft-Matter Material Chemistry and Function Manufacturing, School of Chemistry and Chemical Engineering, Southwest University Chongqing 400715 China
| | - Zhu-Lian Wu
- Key Laboratory of Applied Chemistry of Chongqing Municipality, Chongqing Key Laboratory of Soft-Matter Material Chemistry and Function Manufacturing, School of Chemistry and Chemical Engineering, Southwest University Chongqing 400715 China
| | - Tian Cai
- Key Laboratory of Applied Chemistry of Chongqing Municipality, Chongqing Key Laboratory of Soft-Matter Material Chemistry and Function Manufacturing, School of Chemistry and Chemical Engineering, Southwest University Chongqing 400715 China
| | - Wei Wen
- Key Laboratory of Applied Chemistry of Chongqing Municipality, Chongqing Key Laboratory of Soft-Matter Material Chemistry and Function Manufacturing, School of Chemistry and Chemical Engineering, Southwest University Chongqing 400715 China
| | - Rong-Xing He
- Key Laboratory of Applied Chemistry of Chongqing Municipality, Chongqing Key Laboratory of Soft-Matter Material Chemistry and Function Manufacturing, School of Chemistry and Chemical Engineering, Southwest University Chongqing 400715 China
| | - Qi-Xiang Guo
- Key Laboratory of Applied Chemistry of Chongqing Municipality, Chongqing Key Laboratory of Soft-Matter Material Chemistry and Function Manufacturing, School of Chemistry and Chemical Engineering, Southwest University Chongqing 400715 China
| |
Collapse
|
4
|
Laboratory Scale Continuous Flow Systems for the Enantioselective Phase Transfer Catalytic Synthesis of Quaternary Amino Acids. Molecules 2023; 28:molecules28031002. [PMID: 36770669 PMCID: PMC9920360 DOI: 10.3390/molecules28031002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/11/2023] [Accepted: 01/17/2023] [Indexed: 01/20/2023] Open
Abstract
The use of stereoselective phase-transfer catalysis as a reliable method for the enantioselective synthesis of optically active α-amino acid derivatives using achiral Schiff base esters has been well-developed in batch in the last 40 years. Recently, continuous flow technology has become of great interest in the academy and industry, since it offers safer process operating conditions and higher efficiency compared to a traditional batch processing. Herein, we wish to report the first example of enantioselective phase transfer benzylation of alanine Schiff base ester, under continuous flow conditions. Two different methodologies were investigated: a liquid-solid phase transfer catalytic benzylation using a packed-bed reactor and a liquid-liquid phase transfer catalytic benzylation in continuous stirred-tank reactors. Liquid-liquid phase transfer process in flow showed slightly better productivity than the batch process, while solid-liquid phase transfer benzylation proved much more advantageous in terms of productivity and space-time yield. Furthermore, continuous flow system allowed the isolation of benzylated product without any work up, with a significant simplification of the process. In both cases, phase transfer asymmetric benzylation promoted by Maruoka catalyst demonstrated high enantioselectivity of target quaternary amino ester in flow, up to 93% ee.
Collapse
|
5
|
Wang Y, Wang S, Wu Y, Zhao T, Liu J, Zheng J, Wang L, Lv J, Zhang T. Fast, highly enantioselective, and sustainable fluorination of 4-substituted pyrazolones catalyzed by amide-based phase-transfer catalysts. Org Chem Front 2023. [DOI: 10.1039/d3qo00269a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
Abstract
Highly enantioselective and sustainable fluorination of 4-substituted pyrazolones has been developed by amide-based phase-transfer catalysts.
Collapse
Affiliation(s)
- Yakun Wang
- School of Pharmacy, Xinxiang Medical University, Xinxiang, Henan 453003, P.R. China
| | - Shuaifei Wang
- School of Pharmacy, Xinxiang Medical University, Xinxiang, Henan 453003, P.R. China
| | - Yufeng Wu
- School of Chemical Engineering, Dalian University of Technology, Dalian, Liaoning 116024, P.R. China
| | - Ting Zhao
- School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, Liaoning 117004, P.R. China
| | - Jie Liu
- School of Pharmacy, Xinxiang Medical University, Xinxiang, Henan 453003, P.R. China
| | - Junlin Zheng
- School of Pharmacy, Xinxiang Medical University, Xinxiang, Henan 453003, P.R. China
| | - Lin Wang
- School of Pharmacy, Xinxiang Medical University, Xinxiang, Henan 453003, P.R. China
| | - Jieli Lv
- School of Pharmacy, Xinxiang Medical University, Xinxiang, Henan 453003, P.R. China
| | - Tao Zhang
- School of Pharmacy, Xinxiang Medical University, Xinxiang, Henan 453003, P.R. China
| |
Collapse
|
6
|
Abstract
The asymmetric alkylation of enolates is a particularly versatile method for the construction of α-stereogenic carbonyl motifs, which are ubiquitous in synthetic chemistry. Over the past several decades, the focus has shifted to the development of new catalytic methods that depart from classical stoichiometric stereoinduction strategies (e.g., chiral auxiliaries, chiral alkali metal amide bases, chiral electrophiles, etc.). In this way, the enantioselective alkylation of prochiral enolates greatly improves the step- and redox-economy of this process, in addition to enhancing the scope and selectivity of these reactions. In this review, we summarize the origin and advancement of catalytic enantioselective enolate alkylation methods, with a directed emphasis on the union of prochiral nucleophiles with carbon-centered electrophiles for the construction of α-stereogenic carbonyl derivatives. Hence, the transformative developments for each distinct class of nucleophile (e.g., ketone enolates, ester enolates, amide enolates, etc.) are presented in a modular format to highlight the state-of-the-art methods and current limitations in each area.
Collapse
Affiliation(s)
- Timothy B Wright
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario K7L 3N6, Canada
| | - P Andrew Evans
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario K7L 3N6, Canada.,Xiangya School of Pharmaceutical Sciences, Central South University, Changsha 410013, Hunan, P. R. of China
| |
Collapse
|
7
|
O'Donnell MJ. Benzophenone Schiff bases of glycine derivatives: Versatile starting materials for the synthesis of amino acids and their derivatives. Tetrahedron 2019. [DOI: 10.1016/j.tet.2019.03.029] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
8
|
Hamkalo M, Fita P, Fedorynski M, Makosza M. Interfacial Generation of a Carbanion: The Key Step of PTC Reaction Directly Observed by Second Harmonic Generation. Chemistry 2018; 24:3975-3979. [PMID: 29383849 DOI: 10.1002/chem.201705597] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Indexed: 11/11/2022]
Abstract
We present the first unambiguous evidence of the interfacial mechanism of phase-transfer catalysis (PTC) by direct observation of the formation of carbanions in the interfacial region between the aqueous and the organic phase by using a surface-sensitive spectroscopic method known as second harmonic generation (SHG). Ion exchange of carbanions adsorbed at the surface after addition of lipophilic tetraalkylammonium salts (TAA) to organic phase and transport of the lipophilic ion-pairs to the organic phase is observed. Results allow for the formulation of a more detailed mechanism of PTC.
Collapse
Affiliation(s)
- Michal Hamkalo
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland.,Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093, Warsaw, Poland
| | - Piotr Fita
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093, Warsaw, Poland
| | - Michal Fedorynski
- Department of Chemistry, Warsaw University of Technology, 00-661, Warsaw, Poland
| | - Mieczyslaw Makosza
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
| |
Collapse
|
9
|
Woo S, Kim YG, Lim B, Oh J, Lee Y, Gwon H, Nahm K. Dimeric cinchona ammonium salts with benzophenone linkers: enantioselective phase transfer catalysts for the synthesis of α-amino acids. RSC Adv 2018; 8:2157-2160. [PMID: 35542601 PMCID: PMC9077251 DOI: 10.1039/c7ra12499f] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 12/30/2017] [Indexed: 12/02/2022] Open
Abstract
Chiral phase transfer catalysts of dimeric cinchona ammonium salts linked with a benzophenone bridge showed high enantioselectivity in the α-alkylation of a glycinate ester under mild industry-applicable conditions: 0.5 mol% PTC and near equivalents of alkyl halide. A dual function of the dimeric quinuclidiniums was proposed for the high efficiency. Novel cinchona-alkaloid derived dimeric phase transfer catalysts (PTC) with benzophenone linkers and their α-alkylation of glycinate esters has been presented.![]()
Collapse
Affiliation(s)
- Seunga Woo
- School of Chemistry and Biochemistry
- Yeungnam University
- Gyeongsan
- Republic of Korea
| | - Yong-Gyun Kim
- School of Chemistry and Biochemistry
- Yeungnam University
- Gyeongsan
- Republic of Korea
| | - Baegeun Lim
- School of Chemistry and Biochemistry
- Yeungnam University
- Gyeongsan
- Republic of Korea
| | - Jiin Oh
- School of Chemistry and Biochemistry
- Yeungnam University
- Gyeongsan
- Republic of Korea
| | - Yeonji Lee
- School of Chemistry and Biochemistry
- Yeungnam University
- Gyeongsan
- Republic of Korea
| | - Hyeri Gwon
- School of Chemistry and Biochemistry
- Yeungnam University
- Gyeongsan
- Republic of Korea
| | - Keepyung Nahm
- School of Chemistry and Biochemistry
- Yeungnam University
- Gyeongsan
- Republic of Korea
| |
Collapse
|
10
|
Pigeaux M, Laporte R, Harrowven DC, Baudoux J, Rouden J. Towards a universal organocatalyst for the synthesis of enantioenriched phenylalanine derivatives by enantioselective decarboxylative protonation. Tetrahedron Lett 2016. [DOI: 10.1016/j.tetlet.2016.09.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
11
|
Zhang XZ, Deng YH, Yan X, Yu KY, Wang FX, Ma XY, Fan CA. Diastereoselective and Enantioselective Synthesis of Unsymmetric β,β-Diaryl-α-Amino Acid Esters via Organocatalytic 1,6-Conjugate Addition of para-Quinone Methides. J Org Chem 2016; 81:5655-62. [PMID: 27224285 DOI: 10.1021/acs.joc.6b00390] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
A novel strategy based on phase transfer catalysis for the diastereoselective and enantioselective direct assembly of unsymmetric β,β-diaryl-α-amino acid esters via 1,6-conjugate addition of para-quinone methides and glycine derivatives is described. This protocol also provides an alternative route to the synthetically interesting functionalized chiral tetrahydroisoquinoline and its analogues.
Collapse
Affiliation(s)
- Xiang-Zhi Zhang
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University , 222 Tianshui Nanlu, Lanzhou 730000, China
| | - Yu-Hua Deng
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences , Lanzhou 730000, China
| | - Xu Yan
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University , 222 Tianshui Nanlu, Lanzhou 730000, China
| | - Ke-Yin Yu
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University , 222 Tianshui Nanlu, Lanzhou 730000, China
| | - Fang-Xin Wang
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University , 222 Tianshui Nanlu, Lanzhou 730000, China
| | - Xiao-Yan Ma
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University , 222 Tianshui Nanlu, Lanzhou 730000, China
| | - Chun-An Fan
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University , 222 Tianshui Nanlu, Lanzhou 730000, China.,State Key Laboratory of Natural and Biomimetic Drugs, Peking University , 38 Xueyuan Lu, Beijing 100191, China
| |
Collapse
|
12
|
Jin KJ, Collum DB. Solid-State and Solution Structures of Glycinimine-Derived Lithium Enolates. J Am Chem Soc 2015; 137:14446-55. [PMID: 26554898 PMCID: PMC4762874 DOI: 10.1021/jacs.5b09524] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A combination of crystallographic, spectroscopic, and computational studies was applied to study the structures of lithium enolates derived from glycinimines of benzophenone and (+)-camphor. The solvents examined included toluene and toluene containing various concentrations of tetrahydrofuran, N,N,N',N'-tetramethylethylenediamine (TMEDA), (R,R)-N,N,N',N'-tetramethylcyclohexanediamine [(R,R)-TMCDA], and (S,S)-N,N,N',N'-tetramethylcyclohexanediamine [(S,S)-TMCDA]. Crystal structures show chelated monomers, symmetric disolvated dimers, S4-symmetric tetramers, and both S6- and D3d-symmetric hexamers. (6)Li NMR spectroscopic studies in conjunction with the method of continuous variations show how these species distribute in solution. Density functional theory computations offer insights into experimentally elusive details.
Collapse
Affiliation(s)
- Kyoung Joo Jin
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301
| | - David B. Collum
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853-1301
| |
Collapse
|
13
|
Metz AE, Kozlowski MC. Recent Advances in Asymmetric Catalytic Methods for the Formation of Acyclic α,α-Disubstituted α-Amino Acids. J Org Chem 2014; 80:1-7. [DOI: 10.1021/jo502408z] [Citation(s) in RCA: 134] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Alison E. Metz
- Department of Chemistry,
Roy and Diana Vagelos Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Marisa C. Kozlowski
- Department of Chemistry,
Roy and Diana Vagelos Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| |
Collapse
|
14
|
Shirakawa S, Yamamoto K, Tokuda T, Maruoka K. Phase-Transfer-Catalyzed Asymmetric α-Arylation of α-Amino Acid Derivatives. ASIAN J ORG CHEM 2014. [DOI: 10.1002/ajoc.201400004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
15
|
Buyck T, Wang Q, Zhu J. Catalytic enantioselective Michael addition of α-aryl-α-isocyanoacetates to vinyl selenone: synthesis of α,α-disubstituted α-amino acids and (+)- and (-)-trigonoliimine A. Angew Chem Int Ed Engl 2013; 52:12714-8. [PMID: 24127295 DOI: 10.1002/anie.201306663] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Indexed: 01/02/2023]
Affiliation(s)
- Thomas Buyck
- Laboratory of Synthesis and Natural Products, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, EPFL-SB-ISIC-LSPN, CH-1015 Lausanne (Switzerland)
| | | | | |
Collapse
|
16
|
Buyck T, Wang Q, Zhu J. Catalytic Enantioselective Michael Addition of α-Aryl-α-Isocyanoacetates to Vinyl Selenone: Synthesis of α,α-Disubstituted α-Amino Acids and (+)- and (−)-Trigonoliimine A. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201306663] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
17
|
Kubota Y, Shirakawa S, Inoue T, Maruoka K. New chiral phase-transfer catalysts possessing a 6,6′-bridged ring on the biphenyl unit: application to the synthesis of α,α-dialkyl-α-amino acids. Tetrahedron Lett 2012. [DOI: 10.1016/j.tetlet.2012.04.127] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
18
|
Hitotsuyanagi Y, Odagiri M, Kato S, Kusano JI, Hasuda T, Fukaya H, Takeya K. Isolation, Structure Determination, and Synthesis of Allo-RA-V and Neo-RA-V, RA-Series Bicyclic Peptides fromRubia cordifoliaL. Chemistry 2012; 18:2839-46. [DOI: 10.1002/chem.201103185] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2011] [Indexed: 11/08/2022]
|
19
|
Alba ANR, Valero G, Calbet T, Font-Bardía M, Moyano A, Rios R. Enantioselective addition of oxazolones to maleimides. An easy entry to quaternary aminoacids. NEW J CHEM 2012. [DOI: 10.1039/c1nj20659a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
20
|
Teng HL, Luo FL, Tao HY, Wang CJ. A Facile Cu(I)/BINAP-Catalyzed Asymmetric Approach to Functionalized Pyroglutamate Derivatives Bearing a Unique Quaternary Stereogenic Center. Org Lett 2011; 13:5600-3. [DOI: 10.1021/ol202326j] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Huai-Long Teng
- College of Chemistry and Molecular Sciences, Wuhan University, 430072, China, and State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Shanghai, 230012, China
| | - Fei-Long Luo
- College of Chemistry and Molecular Sciences, Wuhan University, 430072, China, and State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Shanghai, 230012, China
| | - Hai-Yan Tao
- College of Chemistry and Molecular Sciences, Wuhan University, 430072, China, and State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Shanghai, 230012, China
| | - Chun-Jiang Wang
- College of Chemistry and Molecular Sciences, Wuhan University, 430072, China, and State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Shanghai, 230012, China
| |
Collapse
|
21
|
Vandormael B, De Wachter R, Martins JC, Hendrickx PMS, Keresztes A, Ballet S, Mallareddy JR, Tóth F, Tóth G, Tourwé D. Asymmetric Synthesis and Conformational Analysis by NMR Spectroscopy and MD of Aba- and α-MeAba-Containing Dermorphin Analogues. ChemMedChem 2011; 6:2035-47. [DOI: 10.1002/cmdc.201100314] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Indexed: 11/10/2022]
|
22
|
Shirakawa S, Terao SJ, He R, Maruoka K. Diastereo- and enantioselective conjugate addition of α-substituted nitroacetates to maleimides under base-free neutral phase-transfer conditions. Chem Commun (Camb) 2011; 47:10557-9. [PMID: 21869960 DOI: 10.1039/c1cc14043d] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Highly diastereo- and enantioselective conjugate addition of α-substituted nitroacetates to maleimides under base-free neutral phase-transfer conditions was developed for the synthesis of α,α-disubstituted α-amino acid derivatives.
Collapse
Affiliation(s)
- Seiji Shirakawa
- Laboratory of Synthetic Organic Chemistry, Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto, 606-8502, Japan
| | | | | | | |
Collapse
|
23
|
Palladium catalysed asymmetric alkylation of benzophenone Schiff base glycine esters in ionic liquids. J CHEM SCI 2011. [DOI: 10.1007/s12039-011-0093-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
24
|
Xue ZY, Li QH, Tao HY, Wang CJ. A Facile Cu(I)/TF-BiphamPhos-Catalyzed Asymmetric Approach to Unnatural α-Amino Acid Derivatives Containing gem-Bisphosphonates. J Am Chem Soc 2011; 133:11757-65. [DOI: 10.1021/ja2043563] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Zhi-Yong Xue
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Qing-Hua Li
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Hai-Yan Tao
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
| | - Chun-Jiang Wang
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China
- State Key Laboratory of Elemento-organic Chemistry, Nankai University, Tianjin 300071, China
| |
Collapse
|
25
|
Liu C, Molinski TF. Preparation of α-Amino Acids by Oxidative Oxazoline-Oxazinone Rearrangement-Hydrogenation (OOOH). Scope and Limitations. Chem Asian J 2011; 6:2022-7. [DOI: 10.1002/asia.201100452] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Indexed: 11/05/2022]
|
26
|
Alba AN, Companyó X, Valero G, Moyano A, Rios R. Enantioselective Organocatalytic Addition of Oxazolones to 1,1-Bis(phenylsulfonyl)ethylene: A Convenient Asymmetric Synthesis of Quaternary α-Amino Acids. Chemistry 2010; 16:5354-61. [DOI: 10.1002/chem.200903025] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
27
|
Jew SS, Park HG. Cinchona-based phase-transfer catalysts for asymmetric synthesis. Chem Commun (Camb) 2009:7090-103. [PMID: 19920996 DOI: 10.1039/b914028j] [Citation(s) in RCA: 263] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Phase-transfer catalysis is one of the most useful methodologies for practical syntheses given its operational simplicity and mild reaction conditions that enable its application in industrial processes. Cinchona alkaloids have been a popular, natural source of practical organocatalysts due largely to their excellent commercial availability and low cost. Since the first Cinchona alkaloid-derived phase-transfer catalysts was disclosed in 1981, diverse generations of Cinchona-derived phase-transfer catalysts have been developed and successfully applied to various asymmetric syntheses. In this feature article, we describe the generation of Cinchona-derived chiral phase-transfer catalysts according to the development stages and our efforts toward the design of polymeric Cinchona phase-transfer catalysts, the effects of the electronic functional group incorporated in the catalysts, and their application in asymmetric organic reactions.
Collapse
Affiliation(s)
- Sang-sup Jew
- College of Pharmacy, Seoul National University, Seoul 151-742, Korea.
| | | |
Collapse
|
28
|
Kano T, Kumano T, Maruoka K. Rate enhancement of phase transfer catalyzed conjugate additions by CsCl. Org Lett 2009; 11:2023-5. [PMID: 19348469 DOI: 10.1021/ol900476e] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A rate enhancement of phase transfer catalyzed conjugate additions was accomplished using a catalytic amount of CsCl. The utility of this method was demonstrated in the asymmetric synthesis of glutamic acid derivatives by using a chiral phase transfer catalyst.
Collapse
Affiliation(s)
- Taichi Kano
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan
| | | | | |
Collapse
|
29
|
Scott WL, Alsina J, Audu CO, Babaev E, Cook L, Dage JL, Goodwin LA, Martynow JG, Matosiuk D, Royo M, Smith JG, Strong AT, Wickizer K, Woerly EM, Zhou Z, O'Donnell MJ. Distributed Drug Discovery, Part 2: global rehearsal of alkylating agents for the synthesis of resin-bound unnatural amino acids and virtual D(3) catalog construction. ACTA ACUST UNITED AC 2009; 11:14-33. [PMID: 19105725 PMCID: PMC2651687 DOI: 10.1021/cc800184v] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
![]()
Distributed Drug Discovery (D3) proposes solving large drug discovery problems by breaking them into smaller units for processing at multiple sites. A key component of the synthetic and computational stages of D3 is the global rehearsal of prospective reagents and their subsequent use in the creation of virtual catalogs of molecules accessible by simple, inexpensive combinatorial chemistry. The first section of this article documents the feasibility of the synthetic component of Distributed Drug Discovery. Twenty-four alkylating agents were rehearsed in the United States, Poland, Russia, and Spain, for their utility in the synthesis of resin-bound unnatural amino acids 1, key intermediates in many combinatorial chemistry procedures. This global reagent rehearsal, coupled to virtual library generation, increases the likelihood that any member of that virtual library can be made. It facilitates the realistic integration of worldwide virtual D3 catalog computational analysis with synthesis. The second part of this article describes the creation of the first virtual D3 catalog. It reports the enumeration of 24 416 acylated unnatural amino acids 5, assembled from lists of either rehearsed or well-precedented alkylating and acylating reagents, and describes how the resulting catalog can be freely accessed, searched, and downloaded by the scientific community.
Collapse
Affiliation(s)
- William L Scott
- Department of Chemistry and Chemical Biology, Indiana University-Purdue University, Indianapolis, Indiana 46202-3274, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Kitamura M, Shirakawa S, Arimura Y, Wang X, Maruoka K. Combinatorial Design of Simplified High-Performance Chiral Phase-Transfer Catalysts for Practical Asymmetric Synthesis of α-Alkyl- and α,α-Dialkyl-α-Amino Acids. Chem Asian J 2008; 3:1702-14. [DOI: 10.1002/asia.200800107] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
31
|
QU ZR, XIONG RG. Monomeric Cu(II) Complex Containing Chiral Phase-transfer Catalyst as Ligand and Its Asymmetrically Catalytic Reaction. CHINESE J CHEM 2008. [DOI: 10.1002/cjoc.200890047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
32
|
Chinchilla R, Nájera C, Ortega FJ. Convenient Conditions for the Enantioselective Synthesis of α-Methyl-α-amino Acids with the Use ofCinchonaAmmonium Salts as Phase-Transfer Organocatalysts. European J Org Chem 2007. [DOI: 10.1002/ejoc.200700925] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
33
|
Kukhar' VP, Svistunova NY, Solodenko VA, Soloshonok VA. Asymmetric synthesis of fluorine- and phosphorus-containing analogues of aminoacids. RUSSIAN CHEMICAL REVIEWS 2007. [DOI: 10.1070/rc1993v062n03abeh000017] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
34
|
Abstract
The use of chiral nonracemic onium salts and crown ethers as effective phase-transfer catalysts have been studied intensively primarily for enantioselective carbon-carbon or carbon-heteroatom bond-forming reactions under mild biphasic conditions. An essential issue for optimal asymmetric catalysis is the rational design of catalysts for targeted reaction, which allows generation of a well-defined chiral ion pair that reacts with electrophiles in a highly efficient and stereoselective manner. This concept, together with the synthetic versatility of phase-transfer catalysis, provides a reliable and general strategy for the practical asymmetric synthesis of highly valuable organic compounds.
Collapse
Affiliation(s)
- Takashi Ooi
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan
| | | |
Collapse
|
35
|
|
36
|
Vogt H, Bräse S. Recent approaches towards the asymmetric synthesis of α,α-disubstituted α-amino acids. Org Biomol Chem 2007; 5:406-30. [PMID: 17252120 DOI: 10.1039/b611091f] [Citation(s) in RCA: 321] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The class of alpha,alpha-disubstituted alpha-amino acids has gained considerable attention in the past decades and continues doing so. The ongoing interest in biological and chemical properties of the substance class has inspired the development of many new methodologies for their asymmetric construction, which have not found their way into the general focus of organic chemistry yet. The aim of this review is to provide an overview of the developments in the field since 1998.
Collapse
Affiliation(s)
- Henning Vogt
- Center for Sustainable and Green Chemistry, Department of Chemistry, Building 201, Technical University of Denmark, DK-2800, Lyngby, Denmark
| | | |
Collapse
|
37
|
Vogt H, Baumann T, Nieger M, Bräse S. Direct Asymmetric α-Sulfamidation of α-Branched Aldehydes: A Novel Approach to Enamine Catalysis. European J Org Chem 2006. [DOI: 10.1002/ejoc.200600587] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
38
|
Chinchilla R, Nájera C, Ortega FJ. Improved conditions for the asymmetric synthesis of α-amino acids using Cinchona-derived anthracenylmethyl ammonium salts as chiral phase-transfer organocatalysts. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.tetasy.2006.12.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
39
|
The synthesis and applications of asymmetric phase-transfer catalysts derived from isomannide and isosorbide. Tetrahedron 2005. [DOI: 10.1016/j.tet.2005.02.010] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
40
|
Park HG, Kim MJ, Park MK, Jung HJ, Lee J, Lee YJ, Jeong BS, Lee JH, Yoo MS, Ku JM, Jew SS. Solid-phase synthetic method for (±)-α-amino acids via phase-transfer catalytic alkylation. Tetrahedron Lett 2005. [DOI: 10.1016/j.tetlet.2004.11.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
41
|
The counterion effect in the phase-transfer catalyzed asymmetric synthesis of α-amino acids promoted by anthryl-derived dimeric Cinchona ammonium salts. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/j.tetasy.2004.07.025] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
42
|
Ohshima T, Shibuguchi T, Fukuta Y, Shibasaki M. Catalytic asymmetric phase-transfer reactions using tartrate-derived asymmetric two-center organocatalysts. Tetrahedron 2004. [DOI: 10.1016/j.tet.2004.05.120] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
43
|
|
44
|
Ohshima T. Enantioselective Total Syntheses of Several Bioactive Natural Products Based on the Development of Practical Asymmetric Catalysis. Chem Pharm Bull (Tokyo) 2004; 52:1031-52. [PMID: 15340187 DOI: 10.1248/cpb.52.1031] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
I present herewith enantioselective total syntheses of several bioactive natural products, such as (-)-strychnine, (+)-decursin, (-)-cryptocaryolone diacetate, (-)-fluoxetine, and aeruginosin 298-A, based on practical asymmetric catalyses (Michael reaction, epoxidation, and phase-transfer reaction) that I developed with co-workers in Prof. Shibasaki's group over the past 5 years. In the first part of this review, I discuss the great improvement of catalyst efficiency in an ALB-catalyzed asymmetric Michael reaction of malonate and application to the pre-manufacturing scale (greater than kilogram scale) and enantioselective total synthesis of (-)-strychnine with the development of novel domino cyclization. To broaden the substrate generality of the Michael reaction, we developed a highly stable, storable, and reusable La-O-linked-BINOL complex. Further extension of the reaction using beta-keto ester as a Michael donor was achieved with the development of a La-NR-linked-BINOL complex, thereby improving indole alkaloid syntheses. In the second section, I discuss enantioselective total synthesis of (+)-decursin using catalytic asymmetric epoxidation. To achieve the synthesis, we developed a new La-BINOL-Ph(3)As = O (1:1:1) complex catalyst system, which has much higher reactivity and broader substrate generality than the previously developed catalyst systems. This allowed us to achieve catalytic asymmetric epoxidation of alpha,beta-unsaturated carboxylic acid derivatives with high enantioselectivity and broad substrate generality for the first time by changing the lanthanide metal and reaction conditions. Among them, catalytic asymmetric epoxidation of alpha,beta-unsaturated morpholinyl amides is quite useful in terms of synthetic utility of the corresponding alpha,beta-epoxy morpholinyl amides. Highly catalyst-controlled enantio- or diastereoselective epoxidation of the alpha,beta-unsaturated morpholinyl amides, coupled with diastereoselective reduction of beta-hydroxy ketones, enabled the synthesis of all possible stereoisomers of 1,3-polyol arrays with successful enantioselective total synthesis of several 1,3-polyol natural products, such as (-)-cryptocaryolone diacetate. In addition, the development of a new regioselective epoxide-opening reaction of alpha,beta-epoxy amides to the corresponding alpha- and beta-hydroxy amides enhanced the usefulness of the present epoxidation and was applied to the enantioselective total synthesis of (-)-fluoxetine. In the final section, I report the development of a new asymmetric two-center organocatalyst (TaDiAS) and its application to the enantioselective synthesis of aeruginosin 298-A and its analogues. Because of the remarkable structural diversity of TaDiAS, a practical asymmetric phase-transfer reaction with broad substrate generality was achieved. As a result, we succeeded in developing a highly versatile synthetic method for aeruginosin 298-A and its analogues. Inhibitory activity studies of the compounds against the serine protease trypsin provided preliminary information about their structure-activity relations.
Collapse
Affiliation(s)
- Takashi Ohshima
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan. .-tokyo.ac.jp
| |
Collapse
|
45
|
Kumar S, Ramachandran U. Phase transfer catalyzed asymmetric alkylations of imine glycinamides. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s0957-4166(03)00441-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
46
|
Kanayama T, Yoshida K, Miyabe H, Kimachi T, Takemoto Y. Synthesis of beta-substituted alpha-amino acids with use of iridium-catalyzed asymmetric allylic substitution. J Org Chem 2003; 68:6197-201. [PMID: 12895050 DOI: 10.1021/jo034638f] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The asymmetric synthesis of beta-substituted alpha-amino acids with use of iridium-catalyzed allylic substitution was described. The Ir-catalyzed allylic substitution of diphenylimino glycinate with allylic phosphates proceeded smoothly even at 0 degrees C and gave branch products with high enantioselectivity (up to 97% ee), when chiral bidentate phosphite bearing the 2-ethylthioethyl group was employed. In addition, both diastereomers of the branch products were synthesized stereoselectively by simply switching the base employed. These methods were also applied to the asymmetric synthesis of quaternary alpha-amino acids.
Collapse
Affiliation(s)
- Takatoshi Kanayama
- Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | | | | | | | | |
Collapse
|
47
|
Shibuguchi T, Fukuta Y, Akachi Y, Sekine A, Ohshima T, Shibasaki M. Development of new asymmetric two-center catalysts in phase-transfer reactions. Tetrahedron Lett 2002. [DOI: 10.1016/s0040-4039(02)02416-4] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
48
|
Nakoji M, Kanayama T, Okino T, Takemoto Y. Pd-catalyzed asymmetric allylic alkylation of glycine imino ester using a chiral phase-transfer catalyst. J Org Chem 2002; 67:7418-23. [PMID: 12375973 DOI: 10.1021/jo0260645] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Pd-catalyzed asymmetric allylic alkylation of the glycine imino ester 1a has been developed using a chiral quaternary ammonium salt 3d without chiral phosphine ligands. The proper choice of the achiral Pd ligand, P(OPh)3, is important to achieve high enantioselectivity. By this method with the dual catalysts, numerous enantiomerically enriched alpha-allylic amino acids 4a-h could be prepared with comparable to higher enantioselectivity than that of the conventional asymmetric alkylation of 1a. In addition, the Pd-catalyzed reaction of 1a with 1-phenyl-2-propenyl acetate 2i afforded the branch product 6 with high enantio- and diastereoselectivity (>95% de, 85% ee).
Collapse
Affiliation(s)
- Masayoshi Nakoji
- Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | | | | | | |
Collapse
|
49
|
Unexpected metal base-dependent inversion of the enantioselectivity in the asymmetric synthesis of α-amino acids using phase-transfer catalysts derived from cinchonidine. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s0957-4166(02)00611-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
50
|
New dimeric anthracenyl-derived Cinchona quaternary ammonium salts as phase-transfer catalysts for the asymmetric synthesis of α-amino acids. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s0957-4166(02)00211-2] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|