301
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Zheng C, Zhuo CX, You SL. Mechanistic insights into the Pd-catalyzed intermolecular asymmetric allylic dearomatization of multisubstituted pyrroles: understanding the remarkable regio- and enantioselectivity. J Am Chem Soc 2014; 136:16251-9. [PMID: 25339156 DOI: 10.1021/ja5080135] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In this article we report a comprehensive density functional theory study on the Pd-catalyzed intermolecular asymmetric allylic dearomatization reactions of multisubstituted pyrroles. The calculated results are in line with the previous experimental observations (J. Am. Chem. Soc. 2014, 136, 6590), and the remarkable regio- and enantioselectivity are well explained. Of all the potential nucleophilic sites around the multisubstituted pyrrole ring, the reaction always occurs at the position where the HOMO of the molecule distributes most significantly. In contrast to the common view on the enantioselectivity of the Pd-catalyzed asymmetric allylic substitution reactions, we find that the steric interaction between the nucleophile and the chiral ligand does not have the dominating effect on the enantioselectivity of the reaction. Instead, the interaction between the allyl moiety and the incoming nucleophile plays an important role in the enantioselectivity-determining process.
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Affiliation(s)
- Chao Zheng
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences , 345 Lingling Lu, Shanghai 200032, China
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302
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Quintard A, Cheshmedzhieva D, Sanchez Duque MDM, Gaudel-Siri A, Naubron JV, Génisson Y, Plaquevent JC, Bugaut X, Rodriguez J, Constantieux T. Origin of the enantioselectivity in organocatalytic Michael additions of β-ketoamides to α,β-unsaturated carbonyls: a combined experimental, spectroscopic and theoretical study. Chemistry 2014; 21:778-90. [PMID: 25382666 DOI: 10.1002/chem.201404481] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Revised: 09/18/2014] [Indexed: 12/27/2022]
Abstract
The organocatalytic enantioselective conjugate addition of secondary β-ketoamides to α,β-unsaturated carbonyl compounds is reported. Use of bifunctional Takemoto's thiourea catalyst allows enantiocontrol of the reaction leading either to simple Michael adducts or spirocyclic aminals in up to 99 % ee. The origin of the enantioselectivity has been rationalised based on combined DFT calculations and kinetic analysis. This study provides a deeper understanding of the reaction mechanism, which involves a predominant role of the secondary amide proton, and clarifies the complex interactions occurring between substrates and the catalyst.
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Affiliation(s)
- Adrien Quintard
- Aix Marseille Université, Centrale Marseille, CNRS, iSm2 UMR 7313, 13397, Marseille (France). Fax: (+33) 491-289-187
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303
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Caruana L, Kniep F, Johansen TK, Poulsen PH, Jørgensen KA. A New Organocatalytic Concept for Asymmetric α-Alkylation of Aldehydes. J Am Chem Soc 2014; 136:15929-32. [DOI: 10.1021/ja510475n] [Citation(s) in RCA: 228] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Lorenzo Caruana
- Center for Catalysis, Department
of Chemistry, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Florian Kniep
- Center for Catalysis, Department
of Chemistry, Aarhus University, DK-8000 Aarhus C, Denmark
| | | | - Pernille H. Poulsen
- Center for Catalysis, Department
of Chemistry, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Karl Anker Jørgensen
- Center for Catalysis, Department
of Chemistry, Aarhus University, DK-8000 Aarhus C, Denmark
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304
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Tsang ASK, Sanhueza IA, Schoenebeck F. Combining Experimental and Computational Studies to Understand and Predict Reactivities of Relevance to Homogeneous Catalysis. Chemistry 2014; 20:16432-41. [DOI: 10.1002/chem.201404725] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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305
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Zhang P, Wu T, Hou M, Ma J, Liu H, Jiang T, Wang W, Wu C, Han B. The Hydrogenation of Aromatic Compounds under Mild Conditions by Using a Solid Lewis Acid and Supported Palladium Catalyst. ChemCatChem 2014. [DOI: 10.1002/cctc.201402671] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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306
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Blanco V, Leigh DA, Lewandowska U, Lewandowski B, Marcos V. Exploring the Activation Modes of a Rotaxane-Based Switchable Organocatalyst. J Am Chem Soc 2014; 136:15775-80. [DOI: 10.1021/ja509236u] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Victor Blanco
- School of Chemistry, University of Manchester, Oxford
Road, Manchester, M13 9PL, United Kingdom
| | - David A. Leigh
- School of Chemistry, University of Manchester, Oxford
Road, Manchester, M13 9PL, United Kingdom
| | - Urszula Lewandowska
- School of Chemistry, University of Manchester, Oxford
Road, Manchester, M13 9PL, United Kingdom
| | - Bartosz Lewandowski
- School of Chemistry, University of Manchester, Oxford
Road, Manchester, M13 9PL, United Kingdom
| | - Vanesa Marcos
- School of Chemistry, University of Manchester, Oxford
Road, Manchester, M13 9PL, United Kingdom
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307
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Martínez JI, Villar L, Uria U, Carrillo L, Reyes E, Vicario JL. Bifunctional Squaramide Catalysts with the Same Absolute Chirality for the Diastereodivergent Access to Densely Functionalised Cyclohexanes through Enantioselective Domino Reactions. Synthesis and Mechanistic Studies. Adv Synth Catal 2014. [DOI: 10.1002/adsc.201400502] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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308
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Abbasov ME, Romo D. The ever-expanding role of asymmetric covalent organocatalysis in scalable, natural product synthesis. Nat Prod Rep 2014; 31:1318-27. [PMID: 25042097 PMCID: PMC5470744 DOI: 10.1039/c4np00025k] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Following the turn of the millennium, the role of asymmetric covalent organocatalysis has developed into a scalable, synthetic paradigm galvanizing the synthetic community toward utilization of these methods toward more practical, metal-free syntheses of natural products. A myriad of reports on asymmetric organocatalytic modes of substrate activation relying on small, exclusively organic molecules are delineating what has now become the multifaceted field of organocatalysis. In covalent catalysis, the catalyst and substrate combine to first form a covalent, activated intermediate that enters the catalytic cycle. Following asymmetric bond formation, the chiral catalyst is recycled through hydrolysis or displacement by a pendant group on the newly formed product. Amine- and phosphine-based organocatalysts are the most common examples that have led to a vast array of reaction types. This Highlight provides a brief overview of covalent modes of organocatalysis and applications of scalable versions of these methods applied to the total synthesis of natural products including examples from our own laboratory.
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Affiliation(s)
- Mikail E Abbasov
- Department of Chemistry, Texas A&M University, P.O. Box 30012, College Station, Texas, United States.
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309
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Umeda R, Takahashi Y, Nishiyama Y. Rhenium complex-catalyzed coupling reaction of enol acetates with alcohols. Tetrahedron Lett 2014. [DOI: 10.1016/j.tetlet.2014.09.054] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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310
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Erdmann H, An F, Mayer P, Ofial AR, Lakhdar S, Mayr H. Structures and Reactivities of 2-Trityl- and 2-(Triphenylsilyl)pyrrolidine-Derived Enamines: Evidence for Negative Hyperconjugation with the Trityl Group. J Am Chem Soc 2014; 136:14263-9. [DOI: 10.1021/ja508065e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Hannes Erdmann
- Department
Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse
5-13, 81377 München, Germany
| | - Feng An
- Department
Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse
5-13, 81377 München, Germany
| | - Peter Mayer
- Department
Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse
5-13, 81377 München, Germany
| | - Armin R. Ofial
- Department
Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse
5-13, 81377 München, Germany
| | - Sami Lakhdar
- Department
Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse
5-13, 81377 München, Germany
- Laboratoire
de Chimie Moléculaire et Thio-organique, UMR CNRS 6507, 6 Boulevard
Maréchal Juin, 14050 Caen, France
| | - Herbert Mayr
- Department
Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse
5-13, 81377 München, Germany
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311
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Willoughby PH, Niu D, Wang T, Haj MK, Cramer CJ, Hoye TR. Mechanism of the reactions of alcohols with o-benzynes. J Am Chem Soc 2014; 136:13657-65. [PMID: 25232890 PMCID: PMC4183651 DOI: 10.1021/ja502595m] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
![]()
We
have studied reactions of secondary and primary alcohols with
benzynes generated by the hexadehydro-Diels–Alder (HDDA) reaction.
These alcohols undergo competitive addition vs dihydrogen transfer
to produce aryl ethers vs reduced benzenoid products, respectively.
During the latter process, an equivalent amount of oxidized ketone
(or aldehyde) is formed. Using deuterium labeling studies, we determined
that (i) it is the carbinol C–H and adjacent O–H hydrogen
atoms that are transferred during this process and (ii) the mechanism
is consistent with a hydride-like transfer of the C–H. Substrates
bearing an internal trap attached to the reactive, HDDA-derived benzyne
intermediate were used to probe the kinetic order of the alcohol trapping
agent in the H2-transfer as well as in the alcohol addition
process. The H2-transfer reaction is first order in alcohol.
Our results are suggestive of a concerted H2-transfer process,
which is further supported by density functional theory (DFT) computational
studies and results of a kinetic isotope effect experiment. In contrast,
alcohol addition to the benzyne is second order in alcohol, a previously
unrecognized phenomenon. Additional DFT studies were used to further
probe the mechanistic aspects of the alcohol addition process.
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Affiliation(s)
- Patrick H Willoughby
- Department of Chemistry, Supercomputing Institute, and Chemical Theory Center, University of Minnesota , 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
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312
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Bakalova SM, Gil Santos A. Diels-Alder reactions of chiral isoimidium salts: a computational study. J Org Chem 2014; 79:8202-11. [PMID: 25090582 DOI: 10.1021/jo501407z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Recently, important efforts have been devoted to asymmetric Diels-Alder (DA) cycloadditions. Several chiral auxiliaries and catalysts were tested, originating a multitude of selectivities. Here, we study the ability of the isoimidium group as a dienophile activator in DA reactions, as well as its behavior in the induction of selectivity, when incorporated in chiral auxiliary units. We study dienophiles attached to isoimidium auxiliaries derived from (2R,5R)-2,5-diphenylpyrrolidine and from (R)-bis((R)-1-phenylethyl)amine, and show that they lead to low activation energies in DA additions to different dienes. Reported experimental regio- and endo/exo selectitivites are also fully rationalized. While diastereoselectivities originated by (2R,5R)-2,5-diphenylpyrrolidine based dienophiles can easily be rationalized by a C2 symmetric transition state, several transition states have to be simultaneously accounted for the rationalization of the selectivity obtained with dienophiles based on (R)-bis((R)-1-phenylethyl)amine. In this case, the C2 symmetric structure leads to opposite selectivities to those experimentally observed. Thus, while the structures of the dienophiles derived from these two amines seem similar, their behavior in the induction of stereoselectivity in DA reactions is quite different. Our models, which substantially differ from those previously proposed in the literature, can also be adapted to other reactions in which this type of chiral auxiliaries is used.
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Affiliation(s)
- Snezhana M Bakalova
- REQUIMTE, CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova Lisboa , 2829-516 Caparica, Portugal
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313
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Allen S, Hsieh SY, Gutierrez O, Bode JW, Kozlowski MC. Concerted amidation of activated esters: reaction path and origins of selectivity in the kinetic resolution of cyclic amines via N-heterocyclic carbenes and hydroxamic acid cocatalyzed acyl transfer. J Am Chem Soc 2014; 136:11783-91. [PMID: 25050843 PMCID: PMC4140451 DOI: 10.1021/ja505784w] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Indexed: 01/18/2023]
Abstract
The N-heterocyclic carbene and hydroxamic acid cocatalyzed kinetic resolution of cyclic amines generates enantioenriched amines and amides with selectivity factors up to 127. In this report, a quantum mechanical study of the reaction mechanism indicates that the selectivity-determining aminolysis step occurs via a novel concerted pathway in which the hydroxamic acid plays a key role in directing proton transfer from the incoming amine. This modality was found to be general in amide bond formation from a number of activated esters including those generated from HOBt and HOAt, reagents that are broadly used in peptide coupling. For the kinetic resolution, the proposed model accurately predicts the faster reacting enantiomer. A breakdown of the steric and electronic control elements shows that a gearing effect in the transition state is responsible for the observed selectivity.
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Affiliation(s)
- Scott
E. Allen
- Department
of Chemistry, Roy and Diana Vagelos Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Sheng-Ying Hsieh
- Laboratorium
für Organische Chemie, ETH-Zürich, Zürich 8093, Switzerland
| | - Osvaldo Gutierrez
- Department
of Chemistry, Roy and Diana Vagelos Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Jeffrey W. Bode
- Laboratorium
für Organische Chemie, ETH-Zürich, Zürich 8093, Switzerland
| | - Marisa C. Kozlowski
- Department
of Chemistry, Roy and Diana Vagelos Laboratories, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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314
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Ren B, Rahm M, Zhang X, Zhou Y, Dong H. Regioselective Acetylation of Diols and Polyols by Acetate Catalysis: Mechanism and Application. J Org Chem 2014; 79:8134-42. [DOI: 10.1021/jo501343x] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Bo Ren
- Key Laboratory for Large-Format Battery Materials and System, Ministry of Education, School of Chemistry & Chemical Engineering, Huazhong University of Science & Technology, Luoyu Road 1037, Wuhan 430074, People’s Republic of China
| | - Martin Rahm
- Department
of Chemistry and Chemical Biology, Cornell University, Baker Laboratory, Ithaca 14853, New York, United States
- Department
of Applied Physical Chemistry, KTH-Royal Institute of Technology, Teknikringen 30, 10044 Stockholm, Sweden
| | - Xiaoling Zhang
- Key Laboratory for Large-Format Battery Materials and System, Ministry of Education, School of Chemistry & Chemical Engineering, Huazhong University of Science & Technology, Luoyu Road 1037, Wuhan 430074, People’s Republic of China
| | - Yixuan Zhou
- Key Laboratory for Large-Format Battery Materials and System, Ministry of Education, School of Chemistry & Chemical Engineering, Huazhong University of Science & Technology, Luoyu Road 1037, Wuhan 430074, People’s Republic of China
| | - Hai Dong
- Key Laboratory for Large-Format Battery Materials and System, Ministry of Education, School of Chemistry & Chemical Engineering, Huazhong University of Science & Technology, Luoyu Road 1037, Wuhan 430074, People’s Republic of China
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315
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Kojima S, Banden N, Yamamoto Y. A Highly Efficient Cooperative Effect in an Acylation Catalyst Bearing Weak Lewis Base and Lewis Acid Sites. CHEM LETT 2014. [DOI: 10.1246/cl.140343] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Satoshi Kojima
- Department of Chemistry, Graduate School of Science, Hiroshima University
- Center for Quantum Life Sciences, Hiroshima University
| | - Narumi Banden
- Department of Chemistry, Graduate School of Science, Hiroshima University
| | - Yohsuke Yamamoto
- Department of Chemistry, Graduate School of Science, Hiroshima University
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316
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Lam YH, Houk KN. How cinchona alkaloid-derived primary amines control asymmetric electrophilic fluorination of cyclic ketones. J Am Chem Soc 2014; 136:9556-9. [PMID: 24967514 PMCID: PMC4105079 DOI: 10.1021/ja504714m] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Indexed: 12/31/2022]
Abstract
The origin of selectivity in the α-fluorination of cyclic ketones catalyzed by cinchona alkaloid-derived primary amines is determined with density functional calculations. The chair preference of a seven-membered ring at the fluorine transfer transition state is key in determining the sense and level of enantiofacial selectivity.
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Affiliation(s)
- Yu-hong Lam
- Department
of Chemistry and
Biochemistry, University of California,
Los Angeles, 607 Charles
E. Young Drive East, Los Angeles, California 90095-1569, United States
| | - K. N. Houk
- Department
of Chemistry and
Biochemistry, University of California,
Los Angeles, 607 Charles
E. Young Drive East, Los Angeles, California 90095-1569, United States
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317
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Wang Y, Ji S, Wei K, Lin J. Epiandrosterone-derived prolinamide as an efficient asymmetric catalyst for Michael addition reactions of aldehydes to nitroalkenes. RSC Adv 2014. [DOI: 10.1039/c4ra03075c] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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318
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Davis RL, Stiller J, Naicker T, Jiang H, Jørgensen KA. Asymmetric organocatalytic epoxidations: reactions, scope, mechanisms, and applications. Angew Chem Int Ed Engl 2014; 53:7406-26. [PMID: 24919420 DOI: 10.1002/anie.201400241] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Indexed: 12/26/2022]
Abstract
Chiral epoxides serve as versatile building blocks in the synthesis of complex organic frameworks. The high strain imposed by the three-membered ring system makes epoxides prone to a variety of nucleophilic ring-opening reactions. Since the development of the Sharpless epoxidation, there have been many important contributions and advances in this area. With the rapid development of the field of asymmetric organocatalysis, a wide range of organocatalysts is now able to catalyze the epoxidation of broad class of unsaturated carbonyl compounds. In this Minireview, recent progress in the development of organocatalytic asymmetric epoxidation methods, the proposed mechanisms of these reactions and their applications as intermediates is reported.
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Affiliation(s)
- Rebecca L Davis
- Center for Catalysis, Department of Chemistry, Aarhus University, 8000 Aarhus C (Denmark); Department of Chemistry, University of Manitoba, Winnipeg, Manitoba, R3T 2N2 (Canada)
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319
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Davis RL, Stiller J, Naicker T, Jiang H, Jørgensen KA. Organokatalytische asymmetrische Epoxidierungen - Reaktionen, Mechanismen und Anwendungen. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201400241] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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320
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Wang Y, Wei D, Li Z, Zhu Y, Tang M. DFT study on the mechanisms and diastereoselectivities of Lewis acid-promoted ketene-alkene [2 + 2] cycloadditions: what is the role of Lewis acid in the ketene and C = X (X = O, CH₂, and NH) [2 + 2] cycloaddition reactions? J Phys Chem A 2014; 118:4288-300. [PMID: 24874716 DOI: 10.1021/jp500358m] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The detailed mechanisms and diastereoselectivities of Lewis acid-promoted ketene-alkene [2 + 2] cycloaddition reactions have been studied by density functional theory (DFT). Four possible reaction channels, including two noncatalyzed diastereomeric reaction channels (channels A and B) and two Lewis acid (LA) ethylaluminum dichloride (EtAlCl2) catalyzed diastereomeric reaction channels (channels C and D), have been investigated in this work. The calculated results indicate that channel A (associated with product R-configurational cycloputanone) is more energy favorable than channel B (associated with the other product S-configurational cyclobutanone) under noncatalyzed condition, but channel D leading to S-configurational cyclobutanone is more energy-favorable than channel C, leading to R-configurational cycloputanone under a LA-promoted condition, which is consistent with the experimental results. And Lewis acid can make the energy barrier of ketene-alkene [2 + 2] cycloaddition much lower. In order to explore the role of LA in ketene and C = X (X = O, CH2, and NH) [2 + 2] cycloadditions, we have tracked and compared the interaction modes of frontier molecular orbitals (FMOs) along the intrinsic reaction coordinate (IRC) under the two different conditions. Besides by reducing the energy gap between the FMOs of the reactants, our computational results demonstrate that Lewis acid lowers the energy barrier of the ketene and C = X [2 + 2] cycloadditions by changing the overlap modes of the FMOs, which is remarkably different from the traditional FMO theory. Furthermore, analysis of global reactivity indexes has also been performed to explain the role of LA catalyst in the ketene-alkene [2 + 2] cycloaddition reaction.
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Affiliation(s)
- Yang Wang
- The College of Chemistry and Molecular Engineering, Center of Computational Chemistry, Zhengzhou University , Zhengzhou, Henan Province 450001, P.R. China
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321
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Link A, Sparr C. Organokatalytische atropselektive Aldolkondensation: Synthese axial-chiraler Biaryle durch Arenbildung. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201402441] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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322
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Link A, Sparr C. Organocatalytic Atroposelective Aldol Condensation: Synthesis of Axially Chiral Biaryls by Arene Formation. Angew Chem Int Ed Engl 2014; 53:5458-61. [DOI: 10.1002/anie.201402441] [Citation(s) in RCA: 156] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Indexed: 11/08/2022]
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323
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Acharya AK, Chang YA, Jones GO, Rice JE, Hedrick JL, Horn HW, Waymouth RM. Experimental and Computational Studies on the Mechanism of Zwitterionic Ring-Opening Polymerization of δ-Valerolactone with N-Heterocyclic Carbenes. J Phys Chem B 2014; 118:6553-60. [DOI: 10.1021/jp500200b] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Ashwin K. Acharya
- Department
of Chemistry, University of Chicago, 5735 South Ellis Avenue, Room GHJ
222, Chicago, Illinois 60637, United States
| | - Young A. Chang
- Department
of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Gavin O. Jones
- IBM
Research - Almaden, 650
Harry Road, San Jose, California 95120, United States
| | - Julia E. Rice
- IBM
Research - Almaden, 650
Harry Road, San Jose, California 95120, United States
| | - James L. Hedrick
- IBM
Research - Almaden, 650
Harry Road, San Jose, California 95120, United States
| | - Hans W. Horn
- IBM
Research - Almaden, 650
Harry Road, San Jose, California 95120, United States
| | - Robert M. Waymouth
- Department
of Chemistry, Stanford University, Stanford, California 94305, United States
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324
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Yang LJ, Li S, Wang S, Nie J, Ma JA. Nucleophilic Lewis Base Dependent Addition Reactions of Allenoates with Trifluoromethylated Cyclic Ketimines. J Org Chem 2014; 79:3547-58. [DOI: 10.1021/jo500356t] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Li-Jun Yang
- Department
of Chemistry, Key Laboratory of Systems Bioengineering (The Ministry
of Education), Tianjin University, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, People’s Republic of China
| | - Shen Li
- Department
of Chemistry, Key Laboratory of Systems Bioengineering (The Ministry
of Education), Tianjin University, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, People’s Republic of China
| | - Shuai Wang
- Department
of Chemistry, Key Laboratory of Systems Bioengineering (The Ministry
of Education), Tianjin University, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, People’s Republic of China
| | - Jing Nie
- Department
of Chemistry, Key Laboratory of Systems Bioengineering (The Ministry
of Education), Tianjin University, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, People’s Republic of China
| | - Jun-An Ma
- Department
of Chemistry, Key Laboratory of Systems Bioengineering (The Ministry
of Education), Tianjin University, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, People’s Republic of China
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325
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Kemppainen EK, Sahoo G, Piisola A, Hamza A, Kótai B, Pápai I, Pihko PM. Mukaiyama-Michael Reactions withtrans-2,5-Diarylpyrrolidine Catalysts: Enantioselectivity Arises from Attractive Noncovalent Interactions, Not from Steric Hindrance. Chemistry 2014; 20:5983-93. [DOI: 10.1002/chem.201304240] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Indexed: 11/12/2022]
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326
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Li Z, Wei D, Wang Y, Zhu Y, Tang M. DFT Study on the Mechanisms and Stereoselectivities of the [4 + 2] Cycloadditions of Enals and Chalcones Catalyzed by N-Heterocyclic Carbene. J Org Chem 2014; 79:3069-78. [DOI: 10.1021/jo500194d] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Zhenyu Li
- The College of Chemistry
and Molecular Engineering, Center of Computational Chemistry, Zhengzhou University, Zhengzhou, Henan Province, 450001, P.R. China
| | - Donghui Wei
- The College of Chemistry
and Molecular Engineering, Center of Computational Chemistry, Zhengzhou University, Zhengzhou, Henan Province, 450001, P.R. China
| | - Yang Wang
- The College of Chemistry
and Molecular Engineering, Center of Computational Chemistry, Zhengzhou University, Zhengzhou, Henan Province, 450001, P.R. China
| | - Yanyan Zhu
- The College of Chemistry
and Molecular Engineering, Center of Computational Chemistry, Zhengzhou University, Zhengzhou, Henan Province, 450001, P.R. China
| | - Mingsheng Tang
- The College of Chemistry
and Molecular Engineering, Center of Computational Chemistry, Zhengzhou University, Zhengzhou, Henan Province, 450001, P.R. China
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327
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Blanco V, Leigh DA, Marcos V, Morales-Serna JA, Nussbaumer AL. A Switchable [2]Rotaxane Asymmetric Organocatalyst That Utilizes an Acyclic Chiral Secondary Amine. J Am Chem Soc 2014; 136:4905-8. [DOI: 10.1021/ja501561c] [Citation(s) in RCA: 173] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Victor Blanco
- School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom
| | - David A. Leigh
- School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom
| | - Vanesa Marcos
- School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom
| | - José A. Morales-Serna
- School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom
| | - Alina L. Nussbaumer
- School of Chemistry, University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom
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328
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Jindal G, Sunoj RB. Axially Chiral Imidodiphosphoric Acid Catalyst for Asymmetric Sulfoxidation Reaction: Insights on Asymmetric Induction. Angew Chem Int Ed Engl 2014; 53:4432-6. [DOI: 10.1002/anie.201309532] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2013] [Revised: 01/12/2014] [Indexed: 11/08/2022]
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329
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Jindal G, Sunoj RB. Axially Chiral Imidodiphosphoric Acid Catalyst for Asymmetric Sulfoxidation Reaction: Insights on Asymmetric Induction. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201309532] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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330
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Qiao Y, Han KL. Theoretical investigations toward the tandem reactions of N-aziridinyl imine compounds forming triquinanes via trimethylenemethane diyls: mechanisms and stereoselectivity. Org Biomol Chem 2014; 12:1220-31. [PMID: 24336836 DOI: 10.1039/c3ob42115e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this paper, we have investigated the tandem reaction mechanism for the N-aziridinyl imine compounds forming triquinanes via trimethylenemethane (TMM) diyls in detail. Based on the calculated results, the reaction is initiated by the cleavage of the N-aziridinyl in the substrate, followed by an intramolecular 1,3-dipolar (3 + 2) cycloaddition preferentially leading to a linearly-fused tetrahydrocyclopentapyrazole intermediate. Next, the intermediate loses N2 to form the singlet TMM diyl M3S, which can then undergo another concerted (3 + 2) cycloaddition to generate the linearly-fused cis–trans or cis–syn triquinane products. In addition, M3S can also undergo intersystem crossing to the triplet TMM diyl M3T, and the six possible reaction pathways associated with M3T have also been identified. The calculated results reveal that the cis–trans fused pathway associated with M3S is energetically preferred with the highest free energy barrier of 25.0 kcal mol(−1). In comparison, the cyclization of M3T requires much higher activation free energies (ΔG(≠) = 34.4–57.8 kcal mol(−1)). At the experimental temperature 110 °C, only the linearly-fused cis–trans and cis–syn pathways associated with M3T (ΔG(≠) = 34.4 and 35.5 kcal mol(−1) respectively) are possible. The calculated results also indicate that for both M3S and M3T, the linearly-fused cis–trans triquinane should be the main product, which is consistent with the experimental observation. At last, conformational and NBO analyses on key transition states identified the cis–trans stereocontrol factors. Further calculations indicate that the methyl substituent on the allene group of the reactant substrate improves the stereoselectivity of the reaction but does not affect the rate-determining step.
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Affiliation(s)
- Yan Qiao
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Science, Zhongshan Road 457, Dalian 116023, P. R. China.
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331
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Gualandi A, Mengozzi L, Wilson CM, Cozzi PG. Synergy, Compatibility, and Innovation: Merging Lewis Acids with Stereoselective Enamine Catalysis. Chem Asian J 2014; 9:984-95. [DOI: 10.1002/asia.201301549] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Indexed: 01/03/2023]
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332
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Azuma T, Kobayashi Y, Sakata K, Sasamori T, Tokitoh N, Takemoto Y. Synthesis and Characterization of Binary-Complex Models of Ureas and 1,3-Dicarbonyl Compounds: Deeper Insights into Reaction Mechanisms Using Snap-Shot Structural Analysis. J Org Chem 2014; 79:1805-17. [DOI: 10.1021/jo4028775] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Takumi Azuma
- Graduate
School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan
| | - Yusuke Kobayashi
- Graduate
School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan
| | - Ken Sakata
- Faculty
of Pharmaceutical Sciences, Hoshi University, Ebara, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Takahiro Sasamori
- Institute
for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Norihiro Tokitoh
- Institute
for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Yoshiji Takemoto
- Graduate
School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan
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333
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Song X, Liu AX, Liu SS, Gao WC, Wang MC, Chang J. Enantiopure azetidine-2-carboxamides as organocatalysts for direct asymmetric aldol reactions in aqueous and organic media. Tetrahedron 2014. [DOI: 10.1016/j.tet.2013.12.081] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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334
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335
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Szőllősi G, Csámpai A, Somlai C, Fekete M, Bartók M. Unusual enantioselectivities in heterogeneous organocatalyzed reactions: Reversal of direction using proline di- versus tri-peptides in the aldol addition. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/j.molcata.2013.11.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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336
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Sepúlveda D, Lu T, Wheeler SE. Performance of DFT methods and origin of stereoselectivity in bipyridine N,N′-dioxide catalyzed allylation and propargylation reactions. Org Biomol Chem 2014; 12:8346-53. [DOI: 10.1039/c4ob01719f] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
It is shown that many DFT methods correctly predict the stereoselectivity of bipyridine N,N′-dioxide catalyzed alkylation reactions despite predicting the incorrect low-lying transition state structures. A novel explanation of the origin of stereoselectivity in these reactions is also provided.
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Affiliation(s)
- Diana Sepúlveda
- Department of Chemistry
- Texas A&M University
- College Station, USA
| | - Tongxiang Lu
- Department of Chemistry
- Texas A&M University
- College Station, USA
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337
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Armstrong A, Boto RA, Dingwall P, Contreras-García J, Harvey MJ, Mason NJ, Rzepa HS. The Houk–List transition states for organocatalytic mechanisms revisited. Chem Sci 2014. [DOI: 10.1039/c3sc53416b] [Citation(s) in RCA: 126] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The ten year old Houk–List model for rationalising the origin of stereoselectivity in the organocatalysed intermolecular aldol addition is revisited, using a variety of computational techniques that have been introduced or improved since the original study.
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Affiliation(s)
- Alan Armstrong
- Department of Chemistry
- Imperial College London
- South Kensington Campus
- London, UK
| | - Roberto A. Boto
- Sorbonne Universités
- UPMC Univ Paris 06
- UMR 7616
- Laboratoire de Chimie Théorique
- Paris, France
| | - Paul Dingwall
- Department of Chemistry
- Imperial College London
- South Kensington Campus
- London, UK
| | - Julia Contreras-García
- Sorbonne Universités
- UPMC Univ Paris 06
- UMR 7616
- Laboratoire de Chimie Théorique
- Paris, France
| | - Matt J. Harvey
- High Performance Computing
- ICT services
- Imperial College London
- UK
| | - Nicholas J. Mason
- Department of Chemistry
- Imperial College London
- South Kensington Campus
- London, UK
| | - Henry S. Rzepa
- Department of Chemistry
- Imperial College London
- South Kensington Campus
- London, UK
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338
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Seo UR, Chung YK. Poly(4-vinylimidazolium) iodides: a highly recyclable organocatalyst precursor for benzoin condensation reaction. RSC Adv 2014. [DOI: 10.1039/c4ra05073h] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The development of highly efficient, recyclable poly(4-vinylimidazolium) iodides (2) for the benzoin condensation reaction under mild reaction conditions is discussed: poly(4-vinylN-heterocyclic carbene)s (3) obtained from2showed a higher catalytic activity and could be successfully recovered and reused over seven times without loss of performance.
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Affiliation(s)
- Ue Ryung Seo
- Department of Chemistry
- College of Natural Sciences
- Seoul National University
- Seoul 151-747, Korea
| | - Young Keun Chung
- Department of Chemistry
- College of Natural Sciences
- Seoul National University
- Seoul 151-747, Korea
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339
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Jindal G, Sunoj RB. Rational design of catalysts for asymmetric diamination reaction using transition state modeling. Org Biomol Chem 2014; 12:2745-53. [DOI: 10.1039/c3ob42520g] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
DFT calculations have been used to design chiral phosphoramidite ligands for the asymmetric diamination of vicinal diamines. The substituents at both the 3,3′ positions of the binol framework and the amido nitrogen play a vital role in the stereochemical outcome.
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Affiliation(s)
- Garima Jindal
- Department of Chemistry
- Indian Institute of Technology Bombay
- Mumbai 400076, India
| | - Raghavan B. Sunoj
- Department of Chemistry
- Indian Institute of Technology Bombay
- Mumbai 400076, India
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340
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341
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Stiller J, Poulsen PH, Cruz DC, Dourado J, Davis RL, Jørgensen KA. Organocatalytic [4+2] addition reactions via tetraenamine intermediate. Chem Sci 2014. [DOI: 10.1039/c4sc00081a] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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342
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Johnston RC, Cohen DT, Eichman CC, Scheidt KA, Cheong PHY. Catalytic Kinetic Resolution of a Dynamic Racemate: Highly Stereoselective β-Lactone Formation by N-Heterocyclic Carbene Catalysis. Chem Sci 2014; 5:1974-1982. [PMID: 25045464 DOI: 10.1039/c4sc00317a] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
This study describes the combined experimental and computational elucidation of the mechanism and origins of stereoselectivities in the NHC-catalyzed dynamic kinetic resolution (DKR) of α-substituted-β-ketoesters. Density functional theory computations reveal that the NHC-catalyzed DKR proceeds by two mechanisms, depending on the stereochemistry around the forming bond: 1) a concerted, asynchronous formal (2+2) aldol-lactonization process, or 2) a stepwise spiro-lactonization mechanism where the alkoxide is trapped by the NHC-catalyst. These mechanisms contrast significantly from mechanisms found and postulated in other related transformations. Conjugative stabilization of the electrophile and non-classical hydrogen bonds are key in controlling the stereoselectivity. This reaction constitutes an interesting class of DKRs in which the catalyst is responsible for the kinetic resolution to selectively and irreversibly capture an enantiomer of a substrate undergoing rapid racemization with the help of an exogenous base.
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Affiliation(s)
- Ryne C Johnston
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR, 97331, USA
| | - Daniel T Cohen
- Department of Chemistry, Center for Molecular Innovation and Drug Discovery, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA
| | - Chad C Eichman
- Department of Chemistry, Center for Molecular Innovation and Drug Discovery, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA
| | - Karl A Scheidt
- Department of Chemistry, Center for Molecular Innovation and Drug Discovery, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA
| | - Paul Ha-Yeon Cheong
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, OR, 97331, USA
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343
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Calleja J, González-Pérez AB, de Lera ÁR, Álvarez R, Fañanás FJ, Rodríguez F. Enantioselective synthesis of hexahydrofuro[3,2-c] quinolines through a multicatalytic and multicomponent process. A new “aromatic sandwich” model for BINOL-phosphoric acid catalyzed reactions. Chem Sci 2014. [DOI: 10.1039/c3sc52891j] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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344
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Fan YC, Kwon O. Advances in nucleophilic phosphine catalysis of alkenes, allenes, alkynes, and MBHADs. Chem Commun (Camb) 2013; 49:11588-619. [PMID: 24196409 PMCID: PMC3896345 DOI: 10.1039/c3cc47368f] [Citation(s) in RCA: 348] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In nucleophilic phosphine catalysis, tertiary phosphines undergo conjugate additions to activated carbon-carbon multiple bonds to form β-phosphonium enolates, β-phosphonium dienolates, β-phosphonium enoates, and vinyl phosphonium ylides as intermediates. When these reactive zwitterionic species react with nucleophiles and electrophiles, they may generate carbo- and heterocycles with multifarious molecular architectures. This article describes the reactivities of these phosphonium zwitterions, the applications of phosphine catalysis in the syntheses of biologically active compounds and natural products, and recent developments in the enantioselective phosphine catalysis.
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Affiliation(s)
- Yi Chiao Fan
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, USA.
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345
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Kamachi T, Yoshizawa K. Enantioselective Alkylation by Binaphthyl Chiral Phase-Transfer Catalysts: A DFT-Based Conformational Analysis. Org Lett 2013; 16:472-5. [DOI: 10.1021/ol4033545] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Takashi Kamachi
- Institute for Materials Chemistry
and Engineering and International Research Center for Molecular Systems, Kyushu University, Fukuoka 819-0395, Japan
| | - Kazunari Yoshizawa
- Institute for Materials Chemistry
and Engineering and International Research Center for Molecular Systems, Kyushu University, Fukuoka 819-0395, Japan
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346
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Armacost K, Acevedo O. Exploring the Aldol Reaction using Catalytic Antibodies and “On Water” Organocatalysts from QM/MM Calculations. J Am Chem Soc 2013; 136:147-56. [DOI: 10.1021/ja405614p] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Kira Armacost
- Department
of Chemistry,
Biochemistry, Auburn University, Auburn, Alabama 36849, United States
| | - Orlando Acevedo
- Department
of Chemistry,
Biochemistry, Auburn University, Auburn, Alabama 36849, United States
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347
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Núñez M, Farley AM, Dixon DJ. Bifunctional iminophosphorane organocatalysts for enantioselective synthesis: application to the ketimine nitro-Mannich reaction. J Am Chem Soc 2013; 135:16348-51. [PMID: 24107070 PMCID: PMC3931333 DOI: 10.1021/ja409121s] [Citation(s) in RCA: 149] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Indexed: 12/18/2022]
Abstract
The design, synthesis, and development of a new class of modular, strongly basic, and tunable bifunctional Brønsted base/H-bond-donor organocatalysts are reported. These catalysts incorporate a triaryliminophosphorane as the Brønsted basic moiety and are readily synthesized via a last step Staudinger reaction of a chiral organoazide and a triarylphosphine. Their application to the first general enantioselective organocatalytic nitro-Mannich reaction of nitromethane to unactivated ketone-derived imines allows the enantioselective construction of β-nitroamines possessing a fully substituted carbon atom. The reaction is amenable to multigram scale-up, and the products are useful for the synthesis of enantiopure 1,2-diamine and α-amino acid derivatives.
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Affiliation(s)
- Marta
G. Núñez
- The Department
of Chemistry,
Chemistry Research Laboratory, University
of Oxford, 12 Mansfield
Road, Oxford OX1 3TA, U.K.
| | - Alistair
J. M. Farley
- The Department
of Chemistry,
Chemistry Research Laboratory, University
of Oxford, 12 Mansfield
Road, Oxford OX1 3TA, U.K.
| | - Darren J. Dixon
- The Department
of Chemistry,
Chemistry Research Laboratory, University
of Oxford, 12 Mansfield
Road, Oxford OX1 3TA, U.K.
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348
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Zhou Y, Rahm M, Wu B, Zhang X, Ren B, Dong H. H-bonding activation in highly regioselective acetylation of diols. J Org Chem 2013; 78:11618-22. [PMID: 24164588 DOI: 10.1021/jo402036u] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
H-bonding activation in the regioselective acetylation of vicinal and 1,3-diols is presented. Herein, the acetylation of the hydroxyl group with acetic anhydride can be activated by the formation of H-bonds between the hydroxyl group and anions. The reaction exhibits high regioselectivity when a catalytic amount of tetrabutylammonium acetate is employed. Mechanistic studies indicated that acetate anion forms dual H-bonding complexes with the diol, which facilitates the subsequent regioselective monoacetylation.
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Affiliation(s)
- Yixuan Zhou
- School of Chemistry & Chemical Engineering, Huazhong University of Science & Technology , Luoyu Road 1037, Wuhan 430074, P. R. China
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349
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Grošelj U, Podlipnik Č, Bezenšek J, Svete J, Stanovnik B, Seebach D. Reversal of the Stereochemical Course of 1-Methyl-1H-indole Addition to Cinnamaldehyde withcis-5-Benzyl-(2-fluoromethyl)-2,3-dimethylimidazolidin-4-ones as Catalysts - a Puzzling ‘Fluorine Effect’. Helv Chim Acta 2013. [DOI: 10.1002/hlca.201300332] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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350
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Uematsu R, Maeda S, Taketsugu T. Multiple Reaction Pathways Operating in the Mechanism of Vinylogous Mannich-Type Reaction Activated by a Water Molecule. Chem Asian J 2013; 9:305-12. [DOI: 10.1002/asia.201301065] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Indexed: 11/08/2022]
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