1
|
Warnica JM, Gleason JL. Mimicking enzymatic cation-π interactions in hydrazide catalyst design: access to trans-decalin frameworks. Chem Commun (Camb) 2023; 59:10496-10499. [PMID: 37559565 DOI: 10.1039/d3cc03351a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/11/2023]
Abstract
Chiral bicyclic hydrazide organocatalysts have previously been shown to catalyze the cyclization of (Z)-polyene substrates with high enantioselectivity, but with poor selectivity for the corresponding (E)-polyenes. Here we demonstrate that diazapane carboxylates bearing terphenyl groups efficiently catalyze (E)-polyene bicyclization with enantioselectivities up to 94 : 6 er and with high diastereoselectivity for trans-decalin formation. The catalysts function by simultaneously initiating the cyclization via iminium ion formation and stabilizing intermediates/transition states by cation-π interactions.
Collapse
Affiliation(s)
- Josephine M Warnica
- Department of Chemistry, McGill University, 801 Sherbrooke W., Montreal, QC, H3A 0B8, Canada.
| | - James L Gleason
- Department of Chemistry, McGill University, 801 Sherbrooke W., Montreal, QC, H3A 0B8, Canada.
| |
Collapse
|
2
|
Barrett RRG, Campbell DA, Gleason JL. An Organocatalytic Oxy-Cope/Michael Cascade Reaction. Org Lett 2023; 25:777-781. [PMID: 36701675 DOI: 10.1021/acs.orglett.2c04269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Ethyl diazepane carboxylate catalyzes the oxy-Cope rearrangement of 4-hydroxy- and 4-alkoxy-1,5-hexadiene-2-carboxaldehydes via iminium ion activation. The resulting intermediate undergoes an intramolecular Michael reaction to furnish cyclopentane-containing products. The reaction proceeds with a range of substrates, including both cyclic and acyclic substrates, and tolerates substitution on the vinyl substituent. Substrates fused on a cycloalkane framework undergo net ring expansion/cyclopentannulation with a high degree of stereocontrol via chairlike transition states. The reaction extends iminium organocatalysis to the oxy-Cope rearrangement, embedded within a complexity-generating cascade transformation.
Collapse
Affiliation(s)
- Ryan R G Barrett
- Department of Chemistry, McGill University, 801 Sherbrooke West, Montreal, QC H3A 0B8, Canada
| | - Donald A Campbell
- Department of Chemistry, McGill University, 801 Sherbrooke West, Montreal, QC H3A 0B8, Canada
| | - James L Gleason
- Department of Chemistry, McGill University, 801 Sherbrooke West, Montreal, QC H3A 0B8, Canada
| |
Collapse
|
3
|
Melnyk N, Iribarren I, Mates‐Torres E, Trujillo C. Theoretical Perspectives in Organocatalysis. Chemistry 2022; 28:e202201570. [PMID: 35792702 PMCID: PMC9804221 DOI: 10.1002/chem.202201570] [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: 05/20/2022] [Indexed: 01/05/2023]
Abstract
It is clear that the field of organocatalysis is continuously expanding during the last decades. With increasing computational capacity and new techniques, computational methods have provided a more economic approach to explore different chemical systems. This review offers a broad yet concise overview of current state-of-the-art studies that have employed novel strategies for catalyst design. The evolution of the all different theoretical approaches most commonly used within organocatalysis is discussed, from the traditional approach, manual-driven, to the most recent one, machine-driven.
Collapse
Affiliation(s)
- Nika Melnyk
- School of ChemistryTrinity College DublinCollege GreenDublin2Ireland
| | - Iñigo Iribarren
- School of ChemistryTrinity College DublinCollege GreenDublin2Ireland
| | - Eric Mates‐Torres
- School of ChemistryTrinity College DublinCollege GreenDublin2Ireland
| | - Cristina Trujillo
- School of ChemistryTrinity College DublinCollege GreenDublin2Ireland
| |
Collapse
|
4
|
Zhang YQ, Li YY, Maseras F, Liao RZ. Mechanism and selectivity of photocatalyzed CO 2 reduction by a function-integrated Ru catalyst. Dalton Trans 2022; 51:3747-3759. [PMID: 35168249 DOI: 10.1039/d1dt03825g] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The phosphine-substituted Ru(II) polypyridyl complex, [RuII-(tpy)(pqn)(MeCN)]2+ (RuP), was disclosed to be an efficient photocatalyst for the reduction of CO2 to CO with excellent selectivity. In this work, density functional calculations were performed to elucidate the reaction mechanism and understand the origin of selectivity. The calculations showed that RuP was first excited to the singlet excited state, followed by intersystem crossing to produce a triplet species (3RuIII(L˙-)-S), which was then reduced by the sacrificial electron donor BIH to generate a RuII(L˙-) intermediate. The ligand of RuII(L˙-) was further reduced to produce a RuII(L2-) intermediate. The redox non-innocent nature of the tpy and pqn ligands endows the Ru center with an oxidation state of +2 after two one-electron reductions. RuII(L2-) nucleophilically attacks CO2, in which two electrons are delivered from the ligands to CO2, affording a RuII-COOH species after protonation. This is followed by the protonation of the hydroxyl moiety of RuII-COOH, coupled with the C-O bond cleavage, resulting in the formation of RuII-CO. Ultimately, CO is dissociated after two one-electron reductions. Protonation of RuII(L2-) to generate a RuII-hydride, a critical intermediate for the production of formate and H2, turns out to be kinetically less favorable, even though it is thermodynamically more favorable. This fact is due to the presence of a Ru2+ ion in the reduced catalyst, which disfavors its protonation.
Collapse
Affiliation(s)
- Ya-Qiong Zhang
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, Hubei Key Laboratory of Materials Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
| | - Ying-Ying Li
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, Hubei Key Laboratory of Materials Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
| | - Feliu Maseras
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Avgda. Països Catalans, 16, 43007 Tarragona, Catalonia, Spain
| | - Rong-Zhen Liao
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica, Hubei Key Laboratory of Materials Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
| |
Collapse
|
5
|
Warnica JM, Gleason JL. The stabilized iminium catalyzed ( E)-polyene cyclization: trapping of non-activated terminating groups enabled by cation–π interactions. CAN J CHEM 2022. [DOI: 10.1139/cjc-2021-0150] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A cyclic hydrazide catalyst bearing a pendant anthracene catalyzes the polyene cyclization of 1,5-hexadiene-2-carboxaldehydes. Bicyclic closure proceeds in substrates with non-activated terminating groups that fail to react with simple hydrazide catalysts. Computational analysis shows that stabilization through cation–π interactions throughout the reaction sequence leads to the enhanced reactivity of the catalyst.
Collapse
Affiliation(s)
- Josephine M. Warnica
- Department of Chemistry, McGill University, 801 Sherbrooke W., Montreal, QC H3A 0B8, Canada
- Department of Chemistry, McGill University, 801 Sherbrooke W., Montreal, QC H3A 0B8, Canada
| | - James L. Gleason
- Department of Chemistry, McGill University, 801 Sherbrooke W., Montreal, QC H3A 0B8, Canada
- Department of Chemistry, McGill University, 801 Sherbrooke W., Montreal, QC H3A 0B8, Canada
| |
Collapse
|
6
|
Abstract
Carbon–carbon bond formation by [3,3]-sigmatropic rearrangement is a fundamental and powerful method that has been used to build organic molecules for a long time. Initially, Claisen and Cope rearrangements proceeded at high temperatures with limited scopes. By introducing catalytic systems, highly functionalized substrates have become accessible for forming complex structures under mild conditions, and asymmetric synthesis can be achieved by using chiral catalytic systems. This review describes recent breakthroughs in catalytic [3,3]-sigmatropic rearrangements since 2016. Detailed reaction mechanisms are discussed to enable an understanding of the reactivity and selectivity of the reactions. Finally, this review is inspires the development of new cascade reaction pathways employing catalytic [3,3]-sigmatropic rearrangement as related methodologies for the synthesis of complex functional molecules.
Collapse
|
7
|
Dale HJA, Leach AG, Lloyd-Jones GC. Heavy-Atom Kinetic Isotope Effects: Primary Interest or Zero Point? J Am Chem Soc 2021; 143:21079-21099. [PMID: 34870970 DOI: 10.1021/jacs.1c07351] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Chemists have many options for elucidating reaction mechanisms. Global kinetic analysis and classic transition-state probes (e.g., LFERs, Eyring) inevitably form the cornerstone of any strategy, yet their application to increasingly sophisticated synthetic methodologies often leads to a wide range of indistinguishable mechanistic proposals. Computational chemistry provides powerful tools for narrowing the field in such cases, yet wholly simulated mechanisms must be interpreted with great caution. Heavy-atom kinetic isotope effects (KIEs) offer an exquisite but underutilized method for reconciling the two approaches, anchoring the theoretician in the world of calculable observables and providing the experimentalist with atomistic insights. This Perspective provides a personal outlook on this synergy. It surveys the computation of heavy-atom KIEs and their measurement by NMR spectroscopy, discusses recent case studies, highlights the intellectual reward that lies in alignment of experiment and theory, and reflects on the changes required in chemical education in the area.
Collapse
Affiliation(s)
- Harvey J A Dale
- EaStChem, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, U.K
| | - Andrew G Leach
- School of Health Sciences, The University of Manchester, Stopford Building, Oxford Road, Manchester M13 9PT, U.K
| | - Guy C Lloyd-Jones
- EaStChem, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, U.K
| |
Collapse
|
8
|
Semenova E, Lahtigui O, Ghiviriga I, Grenning AJ. [3,3] Ring Rearrangement of Oxo- or Aza-Bridged Bicyclo[3.2.1]octene-Based 1,5-Dienes. Org Lett 2021; 23:2263-2267. [PMID: 33689388 DOI: 10.1021/acs.orglett.1c00388] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report that oxo- or aza-bridged alkylidenemalononitrile-cycloheptenes undergo a [3,3] ring rearrangement to yield cyclopenta-fused dihydro-furans or pyrroles. Described herein are the origins of the serendipitous discovery, scope studies, and representative functional group interconversion chemistry.
Collapse
Affiliation(s)
- Evgeniya Semenova
- Department of Chemistry, University of Florida, P.O. Box 117200, Gainesville, Florida 32611, United States
| | - Ouidad Lahtigui
- Department of Chemistry, University of Florida, P.O. Box 117200, Gainesville, Florida 32611, United States
| | - Ion Ghiviriga
- Department of Chemistry, University of Florida, P.O. Box 117200, Gainesville, Florida 32611, United States
| | - Alexander J Grenning
- Department of Chemistry, University of Florida, P.O. Box 117200, Gainesville, Florida 32611, United States
| |
Collapse
|
9
|
Giustra ZX, Chen G, Vasiliu M, Karkamkar A, Autrey T, Dixon DA, Liu SY. A comparison of hydrogen release kinetics from 5- and 6-membered 1,2-BN-cycloalkanes. RSC Adv 2021; 11:34132-34136. [PMID: 35497319 PMCID: PMC9042405 DOI: 10.1039/d1ra07477f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Accepted: 10/12/2021] [Indexed: 11/21/2022] Open
Abstract
The reaction order and Arrhenius activation parameters for spontaneous hydrogen release from cyclic amine boranes, i.e., BN-cycloalkanes, were determined for 1,2-BN-cyclohexane (1) and 3-methyl-1,2-BN-cyclopentane (2) in tetraglyme. Computational analysis identified a mechanism involving catalytic substrate activation by a ring-opened form of 1 or 2 as being consistent with experimental observations. The reaction order and Arrhenius activation parameters for spontaneous hydrogen release from cyclic amine boranes, i.e., BN-cycloalkanes, were determined for 1,2-BN-cyclohexane (1) and 3-methyl-1,2-BN-cyclopentane (2) in tetraglyme.![]()
Collapse
Affiliation(s)
- Zachary X. Giustra
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467-3860, USA
| | - Gang Chen
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467-3860, USA
| | - Monica Vasiliu
- Department of Chemistry, The University of Alabama, Tuscaloosa, Alabama 35487-0036, USA
| | - Abhijeet Karkamkar
- Pacific Northwest National Laboratories, Richland, Washington 99353, USA
| | - Tom Autrey
- Pacific Northwest National Laboratories, Richland, Washington 99353, USA
| | - David A. Dixon
- Department of Chemistry, The University of Alabama, Tuscaloosa, Alabama 35487-0036, USA
| | - Shih-Yuan Liu
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467-3860, USA
| |
Collapse
|
10
|
Wambua V, Hirschi JS, Vetticatt MJ. Rapid Evaluation of the Mechanism of Buchwald-Hartwig Amination and Aldol Reactions Using Intramolecular 13C Kinetic Isotope Effects. ACS Catal 2021; 11:60-67. [PMID: 34659873 DOI: 10.1021/acscatal.0c04752] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A practical approach is introduced for the rapid determination of 13C kinetic isotope effects that utilizes a "designed" reactant with two identical reaction sites. The mechanism of the Buchwald-Hartwig amination of tert-butylbromobenzene with primary and secondary amines is investigated under synthetically relevant catalytic conditions using traditional intermolecular 13C NMR methodology at natural abundance. Switching to 1,4-dibromobenzene, a symmetric bromoarene as the designed reactant, the same experimental 13C KIEs are determined using an intramolecular KIE approach. This rapid methodology for KIE determination requires substantially less material and time compared to traditional approaches. Details of the Buchwald-Hartwig amination mechanism are investigated under varying synthetic conditions, namely a variety of halides and bases. The enantioselectivity-determining step of the l-proline catalyzed aldol reaction is also evaluated using this approach. We expect this mechanistic methodology to gain traction among synthetic chemists as a practical technique to rapidly obtain high-resolution information regarding the transition structure of synthetically relevant reactions under catalytic conditions.
Collapse
Affiliation(s)
- Victor Wambua
- Department of Chemistry, Binghamton University, Binghamton, New York 13902, United States
| | - Jennifer S. Hirschi
- Department of Chemistry, Binghamton University, Binghamton, New York 13902, United States
| | - Mathew J. Vetticatt
- Department of Chemistry, Binghamton University, Binghamton, New York 13902, United States
| |
Collapse
|