1
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Lan R, Yager B, Jee Y, Day CS, Jones AC. Ligand effects, solvent cooperation, and large kinetic solvent deuterium isotope effects in gold(I)-catalyzed intramolecular alkene hydroamination. Beilstein J Org Chem 2024; 20:479-496. [PMID: 38440168 PMCID: PMC10910400 DOI: 10.3762/bjoc.20.43] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 01/12/2024] [Indexed: 03/06/2024] Open
Abstract
Kinetic studies on the intramolecular hydroamination of protected variants of 2,2-diphenylpent-4-en-1-amine were carried out under a variety of conditions with cationic gold catalysts supported by phosphine ligands. The impact of ligand on gold, protecting group on nitrogen, and solvent and additive on reaction rates was determined. The most effective reactions utilized more Lewis basic ureas, and more electron-withdrawing phosphines. A DCM/alcohol cooperative effect was quantified, and a continuum of isotope effects was measured with low KIE's in the absence of deuterated alcoholic solvent, increasing to large solvent KIE's when comparing reactions in pure MeOH to those in pure MeOH-d4. The effects are interpreted both within the context of a classic gold π-activation/protodeauration mechanism and a general acid-catalyzed mechanism without intermediate gold alkyls.
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Affiliation(s)
- Ruichen Lan
- Chemistry, Wake Forest University, 1834 Gulley Rd., Winston-Salem, NC, 27109, USA
| | - Brock Yager
- Chemistry, Wake Forest University, 1834 Gulley Rd., Winston-Salem, NC, 27109, USA
| | - Yoonsun Jee
- Chemistry, Wake Forest University, 1834 Gulley Rd., Winston-Salem, NC, 27109, USA
| | - Cynthia S Day
- Chemistry, Wake Forest University, 1834 Gulley Rd., Winston-Salem, NC, 27109, USA
| | - Amanda C Jones
- Chemistry, Wake Forest University, 1834 Gulley Rd., Winston-Salem, NC, 27109, USA
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2
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Cerveri A, Vettori M, Serafino A, Maestri G. Base-promoted Conia-ene cyclization of propargyl amides. Org Biomol Chem 2023; 21:7311-7315. [PMID: 37671579 DOI: 10.1039/d3ob01107k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/07/2023]
Abstract
We report a tBuOK-promoted synthesis of 1,3-dihydro-2H-pyrrol-2-one and 4-methylenepyrrolidin-2-one systems via Conia-ene like intramolecular cyclization. The method features extremely short reaction times (5 min) and mild reaction conditions (rt), enabling the trapping of a propargyl unit by an amide enolate. An intriguing anionic chain mechanism is at work, which can trigger the isomerization of an exo-alkene giving access to the otherwise elusive endo-product.
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Affiliation(s)
- Alessandro Cerveri
- Università di Parma, Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Parco Area delle Scienze 17/A, 43124 Parma, Italy.
| | - Mattia Vettori
- Università di Parma, Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Parco Area delle Scienze 17/A, 43124 Parma, Italy.
| | - Andrea Serafino
- Università di Parma, Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Parco Area delle Scienze 17/A, 43124 Parma, Italy.
| | - Giovanni Maestri
- Università di Parma, Dipartimento di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Parco Area delle Scienze 17/A, 43124 Parma, Italy.
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3
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Dethe DH, Beeralingappa NC, Siddiqui SA, Chavan PN. Asymmetric Ru/Cinchonine Dual Catalysis for the One-Pot Synthesis of Optically Active Phthalides from Benzoic Acids and Acrylates. J Org Chem 2022; 87:4617-4630. [PMID: 35266689 DOI: 10.1021/acs.joc.1c02961] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Herein, we report the asymmetric Ru/cinchonine dual catalysis that provides straightforward access to enantioselective synthesis of C-3 substituted phthalides via tandem C-H activation/Michael addition cascade. The use of readily accessible and less expensive [RuCl2(p-cym)]2 and cinchonine catalyst for the one-pot assembly of chiral phthalides greatly overcomes the present trend of using highly sophisticated catalysts. The developed method provides access to both enantiomers of a product using pseudoenantiomeric cinchona alkaloids as catalysts streamlining the synthesis of phthalide in both the optically active forms.
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Affiliation(s)
- Dattatraya H Dethe
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | | | - Salman A Siddiqui
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Prakash N Chavan
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
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4
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Ling J, Mara D, Roure B, Laugeois M, Vitale MR. Copper(I)-Catalyzed Dearomative (3 + 2) Cycloaddition of 3-Nitroindoles with Propargylic Nucleophiles: An Access to Cyclopenta[b]indolines. J Org Chem 2020; 85:3838-3848. [DOI: 10.1021/acs.joc.9b03459] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Johanne Ling
- Institute of Chemistry for Life and Health Sciences, PSL Université Paris, CNRS, Chimie ParisTech., 11 rue Pierre et Marie Curie, 75005 Paris, France
| | - David Mara
- Institute of Chemistry for Life and Health Sciences, PSL Université Paris, CNRS, Chimie ParisTech., 11 rue Pierre et Marie Curie, 75005 Paris, France
| | - Baptiste Roure
- Institute of Chemistry for Life and Health Sciences, PSL Université Paris, CNRS, Chimie ParisTech., 11 rue Pierre et Marie Curie, 75005 Paris, France
| | - Maxime Laugeois
- Institute of Chemistry for Life and Health Sciences, PSL Université Paris, CNRS, Chimie ParisTech., 11 rue Pierre et Marie Curie, 75005 Paris, France
| | - Maxime R. Vitale
- Institute of Chemistry for Life and Health Sciences, PSL Université Paris, CNRS, Chimie ParisTech., 11 rue Pierre et Marie Curie, 75005 Paris, France
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5
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Simlandy AK, Ghosh B, Mukherjee S. Enantioselective [4 + 2]-Annulation of Azlactones with Copper-Allenylidenes under Cooperative Catalysis: Synthesis of α-Quaternary α-Acylaminoamides. Org Lett 2019; 21:3361-3366. [DOI: 10.1021/acs.orglett.9b01103] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Amit Kumar Simlandy
- Department of Organic Chemistry, Indian Institute of Science, Bangalore - 560012, India
| | - Biki Ghosh
- Department of Organic Chemistry, Indian Institute of Science, Bangalore - 560012, India
| | - Santanu Mukherjee
- Department of Organic Chemistry, Indian Institute of Science, Bangalore - 560012, India
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6
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Putatunda S, Alegre-Requena JV, Meazza M, Franc M, Rohal'ová D, Vemuri P, Císařová I, Herrera RP, Rios R, Veselý J. Proline bulky substituents consecutively act as steric hindrances and directing groups in a Michael/Conia-ene cascade reaction under synergistic catalysis. Chem Sci 2019; 10:4107-4115. [PMID: 31015949 PMCID: PMC6457335 DOI: 10.1039/c8sc05258a] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 03/03/2019] [Indexed: 12/23/2022] Open
Abstract
In this study, we report a highly stereoselective and versatile synthesis of spiro pyrazolones, promising motifs that are being employed as pharmacophores. The new synthetic strategy merges organocatalysis and metal catalysis to create a synergistic catalysis using proline derivatives and Pd catalysts. This protocol is suitable for late-stage functionalization, which is very important in drug discovery. Additionally, a thorough computational study proved to be very useful to elucidate the function of the different catalysts along the reaction, showing a peculiar feature: the -CPh2OSiMe3 group of the proline catalyst switches its role during the reaction. In the initial Michael reaction, this group plays its commonly-assumed role of bulky blocking group, but the same group generates π-Pd interactions and acts as a directing group in the subsequent Pd-catalyzed Conia-ene reaction. This finding might be very relevant especially for processes with many steps, such as cascade reactions, in which functional groups are assumed to play the same role during all reaction steps.
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Affiliation(s)
- Salil Putatunda
- Department of Organic Chemistry , Faculty of Science , Charles University , Hlavova 2030 , 128 43 Praha 2 , Czech Republic .
| | - Juan V Alegre-Requena
- Laboratorio de Organocatálisis Asimétrica , Departamento de Química Orgánica , Instituto de Síntesis Química y Catálisis Homogénea (ISQCH) , CSIC-Universidad de Zaragoza , C/Pedro Cerbuna 12 , 50009 Zaragoza , Spain .
| | - Marta Meazza
- University of Southampton , School of Chemistry , Highfield Campus , Southampton , SO17 1BJ , UK .
| | - Michael Franc
- Department of Organic Chemistry , Faculty of Science , Charles University , Hlavova 2030 , 128 43 Praha 2 , Czech Republic .
| | - Dominika Rohal'ová
- Department of Organic Chemistry , Faculty of Science , Charles University , Hlavova 2030 , 128 43 Praha 2 , Czech Republic .
| | - Pooja Vemuri
- University of Southampton , School of Chemistry , Highfield Campus , Southampton , SO17 1BJ , UK .
| | - Ivana Císařová
- Department of Inorganic Chemistry , Faculty of Science , Charles University , Hlavova 2030 , 128 43 Praha 2 , Czech Republic
| | - Raquel P Herrera
- Laboratorio de Organocatálisis Asimétrica , Departamento de Química Orgánica , Instituto de Síntesis Química y Catálisis Homogénea (ISQCH) , CSIC-Universidad de Zaragoza , C/Pedro Cerbuna 12 , 50009 Zaragoza , Spain .
| | - Ramon Rios
- University of Southampton , School of Chemistry , Highfield Campus , Southampton , SO17 1BJ , UK .
| | - Jan Veselý
- Department of Organic Chemistry , Faculty of Science , Charles University , Hlavova 2030 , 128 43 Praha 2 , Czech Republic .
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7
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Balaji PV, Brewitz L, Kumagai N, Shibasaki M. Achiral Trisubstituted Thioureas as Secondary Ligands to Cu
I
Catalysts: Direct Catalytic Asymmetric Addition of α‐Fluoronitriles to Imines. Angew Chem Int Ed Engl 2019; 58:2644-2648. [DOI: 10.1002/anie.201812673] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Indexed: 12/27/2022]
Affiliation(s)
| | - Lennart Brewitz
- Institute of Microbial Chemistry(BIKAKEN) 3-14-23 Kamiosaki, Shinagawa-ku Tokyo 141-0021 Japan
| | - Naoya Kumagai
- Institute of Microbial Chemistry(BIKAKEN) 3-14-23 Kamiosaki, Shinagawa-ku Tokyo 141-0021 Japan
| | - Masakatsu Shibasaki
- Institute of Microbial Chemistry(BIKAKEN) 3-14-23 Kamiosaki, Shinagawa-ku Tokyo 141-0021 Japan
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8
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Balaji PV, Brewitz L, Kumagai N, Shibasaki M. Achiral Trisubstituted Thioureas as Secondary Ligands to Cu
I
Catalysts: Direct Catalytic Asymmetric Addition of α‐Fluoronitriles to Imines. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201812673] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
| | - Lennart Brewitz
- Institute of Microbial Chemistry (BIKAKEN) 3-14-23 Kamiosaki, Shinagawa-ku Tokyo 141-0021 Japan
| | - Naoya Kumagai
- Institute of Microbial Chemistry (BIKAKEN) 3-14-23 Kamiosaki, Shinagawa-ku Tokyo 141-0021 Japan
| | - Masakatsu Shibasaki
- Institute of Microbial Chemistry (BIKAKEN) 3-14-23 Kamiosaki, Shinagawa-ku Tokyo 141-0021 Japan
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9
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Zhang YC, Zhang BW, Geng RL, Song J. Enantioselective [3 + 2] Cycloaddition Reaction of Ethynylethylene Carbonates with Malononitrile Enabled by Organo/Metal Cooperative Catalysis. Org Lett 2018; 20:7907-7911. [PMID: 30540196 DOI: 10.1021/acs.orglett.8b03454] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The first catalytic asymmetric decarboxylative [3 + 2] cycloaddition reaction of ethynylethylene carbonates with malononitrile has been developed successfully by an organo/copper cooperative system. This strategy led to a series of optically active polysubstituted dihydrofurans in good yields with high levels of enantioselectivities (up to 99% yield, 97% ee). The presence of the terminal alkynyl and the cyano group in the dihydrofuran products provides a wide scope for further structural transformations. More importantly, this organo/metal cooperative catalytic system will broaden the substrate scope and enable fundamentally new reactions.
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Affiliation(s)
- Yu-Chen Zhang
- Department of Chemistry , University of Science and Technology of China , Hefei 230026 , China
| | - Bo-Wen Zhang
- Department of Chemistry , University of Science and Technology of China , Hefei 230026 , China
| | - Rui-Long Geng
- Department of Chemistry , University of Science and Technology of China , Hefei 230026 , China
| | - Jin Song
- Department of Chemistry , University of Science and Technology of China , Hefei 230026 , China
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10
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Atashkar B, Zolfigol MA, Mallakpour S. Applications of biological urea-based catalysts in chemical processes. MOLECULAR CATALYSIS 2018. [DOI: 10.1016/j.mcat.2018.03.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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11
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Zhang YC, Zhang ZJ, Fan LF, Song J. Enantioselective Decarboxylative Propargylation/Hydroamination Enabled by Organo/Metal Cooperative Catalysis. Org Lett 2018; 20:2792-2795. [DOI: 10.1021/acs.orglett.8b01101] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Yu-Chen Zhang
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, China
| | - Zi-Jing Zhang
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, China
| | - Lian-Feng Fan
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, China
| | - Jin Song
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, China
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12
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Qiu S, Chen L, Jiang H, Zhu S. CuCl/Et3N-Catalyzed Synthesis of Indanone-Fused 2-Methylene Pyrrolidines from Enynals and Propargylamines. Org Lett 2017; 19:4540-4543. [DOI: 10.1021/acs.orglett.7b02121] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Shaotong Qiu
- Key
Laboratory of Functional Molecular Engineering of Guangdong Province,
School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, China
| | - Lianfen Chen
- Key
Laboratory of Functional Molecular Engineering of Guangdong Province,
School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, China
| | - Huanfeng Jiang
- Key
Laboratory of Functional Molecular Engineering of Guangdong Province,
School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, China
| | - Shifa Zhu
- Key
Laboratory of Functional Molecular Engineering of Guangdong Province,
School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, China
- State
Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China
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13
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Singjunla Y, Pigeaux M, Laporte R, Baudoux J, Rouden J. Thioamide-Substituted Cinchona Alkaloids as Efficient Organocatalysts for Asymmetric Decarboxylative Reactions of MAHOs. European J Org Chem 2017. [DOI: 10.1002/ejoc.201700870] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Yuttapong Singjunla
- LCMT, ENSICAEN, UNICAEN, CNRS; Normandie Univ.; 6 Boulevard du Maréchal Juin 14000 Caen France
| | - Morgane Pigeaux
- LCMT, ENSICAEN, UNICAEN, CNRS; Normandie Univ.; 6 Boulevard du Maréchal Juin 14000 Caen France
| | - Romain Laporte
- LCMT, ENSICAEN, UNICAEN, CNRS; Normandie Univ.; 6 Boulevard du Maréchal Juin 14000 Caen France
| | - Jérôme Baudoux
- LCMT, ENSICAEN, UNICAEN, CNRS; Normandie Univ.; 6 Boulevard du Maréchal Juin 14000 Caen France
| | - Jacques Rouden
- LCMT, ENSICAEN, UNICAEN, CNRS; Normandie Univ.; 6 Boulevard du Maréchal Juin 14000 Caen France
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14
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Wang X, Xu L, Xiong F, Wu Y, Chen F. An improved synthesis of (20 S )-camptothecin and its analogue via an asymmetric α-hydroxylation with a chiral organocatalyst. ACTA ACUST UNITED AC 2017. [DOI: 10.1016/j.tetasy.2017.04.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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15
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Grayson MN. Mechanism and Origins of Stereoselectivity in the Cinchona Thiourea- and Squaramide-Catalyzed Asymmetric Michael Addition of Nitroalkanes to Enones. J Org Chem 2017; 82:4396-4401. [PMID: 28319377 DOI: 10.1021/acs.joc.7b00521] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
We report density functional theory calculations that examine the mechanism and origins of stereoselectivity of Soós' landmark discovery from 2005 that cinchona thioureas catalyze the asymmetric Michael addition of nitroalkanes to enones. We show that the electrophile is activated by the catalyst's protonated amine and that the nucleophile binds to the thiourea moiety by hydrogen bonding. These results lead to the correction of published mechanistic work which did not consider this activation mode. We have also investigated the corresponding cinchona squaramide-catalyzed reaction and found that it proceeds by the same mechanism despite the differences in the geometry of the two catalysts' hydrogen-bond-donating groups, which demonstrates the generality of this mechanistic model.
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Affiliation(s)
- Matthew N Grayson
- Centre for Molecular Informatics, Department of Chemistry, University of Cambridge , Lensfield Road, Cambridge CB2 1EW, United Kingdom
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16
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Tanriver G, Dedeoglu B, Catak S, Aviyente V. Computational Studies on Cinchona Alkaloid-Catalyzed Asymmetric Organic Reactions. Acc Chem Res 2016; 49:1250-62. [PMID: 27254097 DOI: 10.1021/acs.accounts.6b00078] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Remarkable progress in the area of asymmetric organocatalysis has been achieved in the last decades. Cinchona alkaloids and their derivatives have emerged as powerful organocatalysts owing to their reactivities leading to high enantioselectivities. The widespread usage of cinchona alkaloids has been attributed to their nontoxicity, ease of use, stability, cost effectiveness, recyclability, and practical utilization in industry. The presence of tunable functional groups enables cinchona alkaloids to catalyze a broad range of reactions. Excellent experimental studies have extensively contributed to this field, and highly selective reactions were catalyzed by cinchona alkaloids and their derivatives. Computational modeling has helped elucidate the mechanistic aspects of cinchona alkaloid catalyzed reactions as well as the origins of the selectivity they induce. These studies have complemented experimental work for the design of more efficient catalysts. This Account presents recent computational studies on cinchona alkaloid catalyzed organic reactions and the theoretical rationalizations behind their effectiveness and ability to induce selectivity. Valuable efforts to investigate the mechanisms of reactions catalyzed by cinchona alkaloids and the key aspects of the catalytic activity of cinchona alkaloids in reactions ranging from pharmaceutical to industrial applications are summarized. Quantum mechanics, particularly density functional theory (DFT), and molecular mechanics, including ONIOM, were used to rationalize experimental findings by providing mechanistic insights into reaction mechanisms. B3LYP with modest basis sets has been used in most of the studies; nonetheless, the energetics have been corrected with higher basis sets as well as functionals parametrized to include dispersion M05-2X, M06-2X, and M06-L and functionals with dispersion corrections. Since cinchona alkaloids catalyze reactions by forming complexes with substrates via hydrogen bonds and long-range interactions, the use of split valence triple-ζ basis sets including diffuse and polarization functions on heavy atoms and polarization functions on hydrogens are recommended. Most of the studies have used the continuum-based models to mimic the condensed phase in which organocatalysts function; in some cases, explicit solvation was shown to yield better quantitative agreement with experimental findings. The conformational behavior of cinchona alkaloids is also highlighted as it is expected to shed light on the origin of selectivity and pave the way to a comprehensive understanding of the catalytic mechanism. The ultimate goal of this Account is to provide an up-to-date overlook on cinchona alkaloid catalyzed chemistry and provide insight for future studies in both experimental and theoretical fields.
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Affiliation(s)
- Gamze Tanriver
- Department
of Chemistry, Bogazici University, Bebek, Istanbul 34342, Turkey
| | - Burcu Dedeoglu
- Foundations
Development Directorate, Sabancı University, Tuzla-Orhanlı, Istanbul 34956, Turkey
| | - Saron Catak
- Department
of Chemistry, Bogazici University, Bebek, Istanbul 34342, Turkey
| | - Viktorya Aviyente
- Department
of Chemistry, Bogazici University, Bebek, Istanbul 34342, Turkey
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17
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Peng Q, Paton RS. Catalytic Control in Cyclizations: From Computational Mechanistic Understanding to Selectivity Prediction. Acc Chem Res 2016; 49:1042-51. [PMID: 27137131 DOI: 10.1021/acs.accounts.6b00084] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
This Account describes the use of quantum-chemical calculations to elucidate mechanisms and develop catalysts to accomplish highly selective cyclization reactions. Chemistry is awash with cyclic molecules, and the creation of rings is central to organic synthesis. Cyclization reactions, the formation of rings by the reaction of two ends of a linear precursor, have been instrumental in the development of predictive models for chemical reactivity, from Baldwin's classification and rules for ring closure to the Woodward and Hoffmann rules based on the conservation of orbital symmetry and beyond. Ring formation provides a productive and fertile testing ground for the exploration of catalytic mechanisms and chemo-, regio-, diastereo-, and enantioselectivity using computational and experimental approaches. This Account is organized around case studies from our laboratory and illustrates the ways in which computations provide a deeper understanding of the mechanisms of catalysis in 5-endo cyclizations and how computational predictions can lead to the development of new catalysts for enhanced stereoselectivities in asymmetric cycloisomerizations. We have explored the extent to which several cation-directed 5-endo ring-closing reactions may be considered as electrocyclic and demonstrated that reaction pathways and magnetic parameters of transition structures computed using quantum chemistry are inconsistent with this notion, instead favoring a polar mechanism. A rare example of selectivity in favor of 5-endo-trig ring closure is shown to result from subtle substrate effects that bias the reactant conformation out-of-plane, limiting the involvement of cyclic conjugation. The mode of action of a chiral ammonium counterion was deduced via conformational sampling of the transition state assembly and involves coordination to the substrate via a series of nonclassical hydrogen bonds. We describe how computational mechanistic understanding has led directly to the discovery of new catalyst structures for enantioselective cycloisomerizations. Calculations have revealed that stepwise C-C bond formation and proton transfer dictate the exclusive endo diastereoselectivity of the intramolecular Michael addition to form 2-azabicyclo[3.3.1]nonane skeletons catalyzed by primary amines. These insights have led to development of a highly enantioselective catalyst with higher atom economy than previous generations. This Account also explores transition-metal-catalyzed cycloisomerizations, where our theoretical investigations have uncovered an unexpected reaction pathway in the [5 + 2] cycloisomerization of ynamides. This has led to the design of new phosphoramidite ligands to enable double-stereodifferentiating cycloisomerizations in both matched and mismatched catalyst-substrate settings. Computational understanding of the factors responsible for the regio-, enantio-, and diasterocontrol is shown to generate tangible predictions leading to an acceleration of catalyst development for selective cyclizations.
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Affiliation(s)
- Qian Peng
- Chemistry
Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K
- Physical
and Theoretical Chemistry Laboratory, University of Oxford, South Parks
Road, Oxford OX1 3QZ, U.K
| | - Robert S. Paton
- Chemistry
Research Laboratory, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K
- Physical
and Theoretical Chemistry Laboratory, University of Oxford, South Parks
Road, Oxford OX1 3QZ, U.K
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18
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Bhaskararao B, Sunoj RB. Origin of Stereodivergence in Cooperative Asymmetric Catalysis with Simultaneous Involvement of Two Chiral Catalysts. J Am Chem Soc 2015; 137:15712-22. [DOI: 10.1021/jacs.5b05902] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Bangaru Bhaskararao
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Raghavan B. Sunoj
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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19
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Lim HN, Dong G. Catalytic Intramolecular Ketone Alkylation with Olefins by Dual Activation. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201507741] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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20
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Lim HN, Dong G. Catalytic Intramolecular Ketone Alkylation with Olefins by Dual Activation. Angew Chem Int Ed Engl 2015; 54:15294-8. [DOI: 10.1002/anie.201507741] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 09/24/2015] [Indexed: 01/03/2023]
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21
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Hack D, Blümel M, Chauhan P, Philipps AR, Enders D. Catalytic Conia-ene and related reactions. Chem Soc Rev 2015; 44:6059-93. [PMID: 26031492 DOI: 10.1039/c5cs00097a] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Since its initial inception, the Conia-ene reaction, known as the intramolecular addition of enols to alkynes or alkenes, has experienced a tremendous development and appealing catalytic protocols have emerged. This review fathoms the underlying mechanistic principles rationalizing how substrate design, substrate activation, and the nature of the catalyst work hand in hand for the efficient synthesis of carbocycles and heterocycles at mild reaction conditions. Nowadays, Conia-ene reactions can be found as part of tandem reactions, and the road for asymmetric versions has already been paved. Based on their broad applicability, Conia-ene reactions have turned into a highly appreciated synthetic tool with impressive examples in natural product synthesis reported in recent years.
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Affiliation(s)
- Daniel Hack
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany.
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Zhao C, Seidel D. Enantioselective A3 Reactions of Secondary Amines with a Cu(I)/Acid–Thiourea Catalyst Combination. J Am Chem Soc 2015; 137:4650-3. [DOI: 10.1021/jacs.5b02071] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Chenfei Zhao
- Department
of Chemistry and
Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
| | - Daniel Seidel
- Department
of Chemistry and
Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854, United States
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23
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Jindal G, Kisan HK, Sunoj RB. Mechanistic Insights on Cooperative Catalysis through Computational Quantum Chemical Methods. ACS Catal 2014. [DOI: 10.1021/cs501688y] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Garima Jindal
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Hemanta K. Kisan
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Raghavan B. Sunoj
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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Fang W, Presset M, Guérinot A, Bour C, Bezzenine-Lafollée S, Gandon V. Cationic gold(i)-catalyzed enantioselective hydroalkylation of unactivated alkenes: influence of the chloride scavenger on the stereoselectivity. Org Chem Front 2014. [DOI: 10.1039/c4qo00112e] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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