1
|
Zhu H, Li S, Jia Y, Jiang J, Hu F, Li L, Cao F, Wang X, Li S, Ouyang G, Tian G, Gong K, Hou G, He W, Zhao Z, Pittman CU, Deng F, Liu M, Sun K, Tang BZ. Pseudo-resonance structures in chiral alcohols and amines and their possible aggregation states. Front Chem 2022; 10:964615. [PMID: 36105310 PMCID: PMC9465258 DOI: 10.3389/fchem.2022.964615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 07/18/2022] [Indexed: 11/13/2022] Open
Abstract
We now report that some chiral compounds, like alcohols, which are not sterically hindered atropisomers nor epimer mixtures, exhibit two sets of simultaneous NMR spectra in CDCl3. Some other chiral alcohols also simultaneously exhibit two different NMR spectra in the solid state because two different conformers, A and B had different sizes because their corresponding bond lengths and angles are different. These structures were confirmed in the same solid state by X-ray. We designate these as pseudo-resonance for a compound exhibiting several different corresponding lengths that simultaneously coexist in the solid state or liquid state. Variable-temperature NMR, 2D NMR methods, X-ray, neutron diffraction, IR, photo-luminesce (PL) and other methods were explored to study whether new aggregation states caused these heretofore unknown pseudo-resonance structures. Finally, eleven chiral alcohols or diols were found to co-exist in pseudo-resonance structures by X-ray crystallography in a search of the CDS database.
Collapse
Affiliation(s)
- Huajie Zhu
- School of Chemical and Pharmaceutical Engineering, Hebei University of Science and Technology, Shijiazhuang, China
- Institute of Life Science and Green Development, Hebei University, Baoding, China
| | - Shengnan Li
- School of Chemical and Pharmaceutical Engineering, Hebei University of Science and Technology, Shijiazhuang, China
- Institute of Life Science and Green Development, Hebei University, Baoding, China
| | - Yunjing Jia
- Institute of Life Science and Green Development, Hebei University, Baoding, China
| | - Juxing Jiang
- Kunming Institute of Botany CAS, Kunming, Yunnan, China
| | - Feiliu Hu
- Institute of Life Science and Green Development, Hebei University, Baoding, China
| | - Longfei Li
- Institute of Life Science and Green Development, Hebei University, Baoding, China
| | - Fei Cao
- Institute of Life Science and Green Development, Hebei University, Baoding, China
| | - Xiaoke Wang
- Institute of Life Science and Green Development, Hebei University, Baoding, China
| | - Shenhui Li
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics CAS, Wuhan, Hubei, China
| | - Guanghui Ouyang
- Institute of Chemistry, Chinese Academy of Sciences, Beijing, China
| | - Gengfang Tian
- Neutron Scattering Laboratory, Department of Nuclear Physics, China Institute of Atomic Energy, Beijing, China
| | - Ke Gong
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics CAS, Dalian, China
| | - Guangjin Hou
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics CAS, Dalian, China
| | - Wei He
- School of Science and Engineering, Shenzhen Institute of Aggregate Science and Technology, The Chinese University of Hong Kong, Shenzhen, China
| | - Zheng Zhao
- School of Science and Engineering, Shenzhen Institute of Aggregate Science and Technology, The Chinese University of Hong Kong, Shenzhen, China
| | - Charles U. Pittman
- Department of Chemistry, Mississippi State University, Starkville, MS, United States
| | - Feng Deng
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics CAS, Wuhan, Hubei, China
| | - Minghua Liu
- Institute of Chemistry, Chinese Academy of Sciences, Beijing, China
| | - Kai Sun
- Neutron Scattering Laboratory, Department of Nuclear Physics, China Institute of Atomic Energy, Beijing, China
| | - Ben Zhong Tang
- School of Science and Engineering, Shenzhen Institute of Aggregate Science and Technology, The Chinese University of Hong Kong, Shenzhen, China
| |
Collapse
|
2
|
Felder S, Wu S, Brom J, Micouin L, Benedetti E. Enantiopure planar chiral [2.2]paracyclophanes: Synthesis and applications in asymmetric organocatalysis. Chirality 2021; 33:506-527. [PMID: 34302702 DOI: 10.1002/chir.23335] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 06/14/2021] [Indexed: 12/20/2022]
Abstract
This short review focuses on enantiopure planar chiral [2.2]paracyclophanes (pCps), a fascinating class of molecules that possess an unusual three-dimensional core and intriguing physicochemical properties. In the first part of the review, different synthetic strategies for preparing optically active pCps are described. Although classical resolution methods based on the synthesis and separation of diastereoisomeric products still dominate the field, recent advances involving the kinetic resolution of racemic compounds and the desymmetrization of meso derivatives open up new possibilities to access enantiopure key intermediates on synthetically useful scales. Due to their advantageous properties including high configurational and chemical stability, [2.2]paracyclophanes are increasingly employed in various research fields, ranging from stereoselective synthesis to material sciences. The applications of [2.2]paracyclophanes in asymmetric organocatalysis are described in the second part of the review. While historically enantiopure pCps have been mainly employed by organic chemists as chiral ligands in transition-metal catalysis, these compounds can also be used as efficient catalysts in metal-free reactions and may inspire the development of new transformations in the near future.
Collapse
Affiliation(s)
- Simon Felder
- Laboratoire de Chimie et Biochimie Pharmacolgiques et Toxicologiques - UMR8601 CNRS, Université de Paris, Paris, France
| | - Shiqi Wu
- Laboratoire de Chimie et Biochimie Pharmacolgiques et Toxicologiques - UMR8601 CNRS, Université de Paris, Paris, France
| | - Jules Brom
- Laboratoire de Chimie et Biochimie Pharmacolgiques et Toxicologiques - UMR8601 CNRS, Université de Paris, Paris, France
| | - Laurent Micouin
- Laboratoire de Chimie et Biochimie Pharmacolgiques et Toxicologiques - UMR8601 CNRS, Université de Paris, Paris, France
| | - Erica Benedetti
- Laboratoire de Chimie et Biochimie Pharmacolgiques et Toxicologiques - UMR8601 CNRS, Université de Paris, Paris, France
| |
Collapse
|
3
|
Weinzierl D, Waser M. Chiral isothiourea-catalyzed kinetic resolution of 4-hydroxy[2.2]paracyclophane. Beilstein J Org Chem 2021; 17:800-804. [PMID: 33889220 PMCID: PMC8042488 DOI: 10.3762/bjoc.17.68] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 04/01/2021] [Indexed: 01/07/2023] Open
Abstract
We herein report a method for the kinetic resolution of racemic 4-hydroxy[2.2]paracyclophane by means of a chiral isothiourea-catalyzed acylation with isobutyric anhydride. This protocol allows for a reasonable synthetically useful s-factor of 20 and provides a novel entry to obtain this interesting planar chiral motive in an enantioenriched manner.
Collapse
Affiliation(s)
- David Weinzierl
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040 Linz, Austria
| | - Mario Waser
- Institute of Organic Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, 4040 Linz, Austria
| |
Collapse
|
6
|
Friedmann CJ, Ay S, Bräse S. Improved Synthesis of Enantiopure 4-Hydroxy[2.2]paracyclophane. J Org Chem 2010; 75:4612-4. [DOI: 10.1021/jo100468s] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Christian J. Friedmann
- Institute of Organic Chemistry, Karlsruhe Institute of Technology, Fritz-Haber-Weg 6, D-76131 Karlsruhe, Germany
| | - Sefer Ay
- Institute of Organic Chemistry, Karlsruhe Institute of Technology, Fritz-Haber-Weg 6, D-76131 Karlsruhe, Germany
| | - Stefan Bräse
- Institute of Organic Chemistry, Karlsruhe Institute of Technology, Fritz-Haber-Weg 6, D-76131 Karlsruhe, Germany
| |
Collapse
|