1
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Li Y, Li X. Theoretical insights into the enantiodivergence induced by chiral phosphoric acid catalysis with a Lewis acid for the synthesis of N-N axially chiral atropisomers. Org Biomol Chem 2024; 22:1654-1661. [PMID: 38295370 DOI: 10.1039/d3ob02011h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2024]
Abstract
A detailed theoretical mechanistic investigation on chiral phosphoric acid (CPA)-catalyzed Paal-Knorr reactions, in the presence and absence of a Lewis acid, for the synthesis of N-N axially chiral atropisomers is described herein. Density functional theory (DFT) studies elucidate that in the absence of a Lewis acid, CPA catalyzes both the initial cyclization and the subsequent dehydroxylation processes, ambiguously identified as the rate-determining step in the reactions. Conversely, when a Lewis acid participates in the reaction, it facilitates the second dehydroxylation process with a significantly lower energy barrier, thereby reversing the rate-determining step to the initial cyclization step. It is noteworthy that in the case of N-aminoindoles, both the S-configurational transition state TS1 in the cyclization step and TS2 in the dehydroxylation process are favourable. In contrast, for the synthesis of a bispyrrole, the R-configurational TS1 and the S-configurational TS2 are dominant. Therefore, the enantiodivergence observed is essentially induced by the reversed rate-determining steps in the absence or presence of a Lewis acid in the case of a bispyrrole. Furthermore, the non-covalent interaction (NCI) and atoms-in-molecules (AIM) analysis of the TS structures reveal that the non-covalent interactions play a pivotal role in determining the enantiodivergence observed in these reactions.
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Affiliation(s)
- Yanze Li
- Department of Chemistry, College of Sciences, Shanghai Engineering Research Center of Organ Repair, Shanghai University, Shanghai 200444, China.
| | - Xinyao Li
- Department of Chemistry, College of Sciences, Shanghai Engineering Research Center of Organ Repair, Shanghai University, Shanghai 200444, China.
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2
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Wang SJ, Wang X, Xin X, Zhang S, Yang H, Wong MW, Lu S. Organocatalytic diastereo- and atroposelective construction of N-N axially chiral pyrroles and indoles. Nat Commun 2024; 15:518. [PMID: 38225235 PMCID: PMC10789812 DOI: 10.1038/s41467-024-44743-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Accepted: 12/28/2023] [Indexed: 01/17/2024] Open
Abstract
The construction of N-N axially chiral motifs is an important research topic, owing to their wide occurrence in natural products, pharmaceuticals and chiral ligands. One efficient method is the atroposelective dihydropyrimidin-4-one formation. We present herein a direct catalytic synthesis of N-N atropisomers with simultaneous creation of contiguous axial and central chirality by oxidative NHC (N-heterocyclic carbenes) catalyzed (3 + 3) cycloaddition. Using our method, we are able to synthesize structurally diverse N-N axially chiral pyrroles and indoles with vicinal central chirality or bearing a 2,3-dihydropyrimidin-4-one moiety in moderate to good yields and excellent enantioselectivities. Further synthetic transformations of the obtained axially chiral pyrroles and indoles derivative products are demonstrated. The reaction mechanism and the origin of enantioselectivity are understood through DFT calculations.
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Affiliation(s)
- Shao-Jie Wang
- Frontiers Science Center for Flexible Electronics (FSCFE), Shaanxi Institute of Flexible Electronics (SIFE) & Shaanxi Institute of Biomedical Materials and Engineering (SIBME), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an, 710072, China
| | - Xia Wang
- Frontiers Science Center for Flexible Electronics (FSCFE), Shaanxi Institute of Flexible Electronics (SIFE) & Shaanxi Institute of Biomedical Materials and Engineering (SIBME), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an, 710072, China
| | - Xiaolan Xin
- Frontiers Science Center for Flexible Electronics (FSCFE), Shaanxi Institute of Flexible Electronics (SIFE) & Shaanxi Institute of Biomedical Materials and Engineering (SIBME), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an, 710072, China
| | - Shulei Zhang
- Frontiers Science Center for Flexible Electronics (FSCFE), Shaanxi Institute of Flexible Electronics (SIFE) & Shaanxi Institute of Biomedical Materials and Engineering (SIBME), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an, 710072, China
| | - Hui Yang
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore
| | - Ming Wah Wong
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore.
| | - Shenci Lu
- Frontiers Science Center for Flexible Electronics (FSCFE), Shaanxi Institute of Flexible Electronics (SIFE) & Shaanxi Institute of Biomedical Materials and Engineering (SIBME), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an, 710072, China.
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3
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Feng J, Liu RR. Catalytic Asymmetric Synthesis of N-N Biaryl Atropisomers. Chemistry 2024; 30:e202303165. [PMID: 37850396 DOI: 10.1002/chem.202303165] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 10/16/2023] [Accepted: 10/18/2023] [Indexed: 10/19/2023]
Abstract
Atropisomers have emerged as important structural scaffolds in natural products, drug design, and asymmetric synthesis. Recently, N-N biaryl atropisomers have drawn increasing interest due to their unique structure and relatively stable axes. However, its asymmetric synthesis remains scarce compared to its well-developed C-C biaryl analogs. In this concept, we summarize the asymmetric synthesis of N-N biaryl atropisomers including N-N pyrrole-pyrrole, N-N pyrrole-indole, N-N indole-indole, and N-N indole-carbazole, during which a series synthetic strategies are highlighted. Also, a synthetic evolution is briefly reviewed and an outlook of N-N biaryl atropisomers synthesis is offered.
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Affiliation(s)
- Jia Feng
- College of Chemistry and Chemical Engineering, Qingdao University, NingXia Road 308#, Qingdao, 266071, China
| | - Ren-Rong Liu
- College of Chemistry and Chemical Engineering, Qingdao University, NingXia Road 308#, Qingdao, 266071, China
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4
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Feng J, Lu CJ, Liu RR. Catalytic Asymmetric Synthesis of Atropisomers Featuring an Aza Axis. Acc Chem Res 2023; 56:2537-2554. [PMID: 37694726 DOI: 10.1021/acs.accounts.3c00419] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
ConspectusAtropisomers bearing a rotation-restricted axis are common structural units in natural products, chiral ligands, and drugs; thus, the prevalence of asymmetric synthesis has increased in recent decades. Research into atropisomers featuring an N-containing axis (N-X atropisomers) remains in its infancy compared with the well-developed C-C atropisomer analogue. Notably, N-X atropisomers could offer divergent scaffolds, which are extremely important in bioactive molecules. The asymmetric synthesis of N-X atropisomers is recognized as both appealing and challenging. Recently, we devoted our efforts to the catalytic asymmetric synthesis of N-X atropisomers, benzimidazole-aryl N-C atropisomers, indole-aryl N-C atropisomers, hydrogen-bond-assisted N-C atropisomers, pyrrole-pyrrole N-N atropisomers, pyrrole-indole N-N atropisomers, and indole-indole N-N atropisomers. To obtain the N-C atropisomers, an asymmetric Buchwald-Hartwig reaction of amidines or enamines was employed. Using a Pd(OAc)2/(S)-BINAP or Pd(OAc)2/(S)-Xyl-BINAP catalyst system, benzimidazole-aryl N-C atropisomers and indole-aryl N-C atropisomers were readily obtained. To address the issue of the reduced stability of the diarylamine axis, a six-membered intramolecular N-H-O hydrogen bond was introduced into the N-C atropisomer scaffold. A tandem N-arylation/oxidation process was used for the chiral phosphoric acid (CPA)-catalyzed asymmetric synthesis of N-aryl quinone atropisomers. For N-N atropisomers, a copper-mediated asymmetric Friedel-Crafts alkylation/arylation reaction was developed. The desymmetrization process was completed successfully via a Cu(OTf)2/chiral bisoxazoline or (CuOTf)·Tol/bis(phosphine) dioxide system, thereby achieving the first catalytic asymmetric synthesis of N/N bipyrrole atropisomers. Asymmetric Buchwald-Hartwig amination of enamines was utilized to provide N-N bisindole atropisomers with excellent stereogenic control. This was the first asymmetric synthesis of N-N atropisomers featuring a bisindole structural scaffold using the de novo indole construction strategy. The asymmetric N-N heterobiaryl atropisomer synthesis was substantially facilitated using palladium-catalyzed transient directing group (TDG)-mediated C-H functionalization. Atropisomeric alkenylation, allylation, or alkynylation was accomplished using the Pd(OAc)2/l-tert-leucine system. Herein, we summarize our work on the palladium-, copper-, and CPA-catalyzed asymmetric syntheses of N-C and N-N atropisomers. Furthermore, the application of our work in the synthesis of bioactive molecule analogues and axially chiral ligands is demonstrated. Subsequently, the stability of the chiral N-containing axis is briefly discussed in terms of single crystals and obtained rotational barriers. Finally, an outlook on the asymmetric N-X atropisomer synthesis is provided.
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Affiliation(s)
- Jia Feng
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, China
| | - Chuan-Jun Lu
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, China
| | - Ren-Rong Liu
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, China
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5
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Li T, Shi L, Wang X, Yang C, Yang D, Song MP, Niu JL. Cobalt-catalyzed atroposelective C-H activation/annulation to access N-N axially chiral frameworks. Nat Commun 2023; 14:5271. [PMID: 37644016 PMCID: PMC10465517 DOI: 10.1038/s41467-023-40978-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 08/17/2023] [Indexed: 08/31/2023] Open
Abstract
The N-N atropisomer, as an important and intriguing chiral system, was widely present in natural products, pharmaceutical lead compounds, and advanced material skeletons. The anisotropic structural characteristics caused by its special axial rotation have always been one of the challenges that chemists strive to overcome. Herein, we report an efficient method for the enantioselective synthesis of N-N axially chiral frameworks via a cobalt-catalyzed atroposelective C-H activation/annulation process. The reaction proceeds under mild conditions by using Co(OAc)2·4H2O as the catalyst with a chiral salicyl-oxazoline (Salox) ligand and O2 as an oxidant, affording a variety of N-N axially chiral products with high yields and enantioselectivities. This protocol provides an efficient approach for the facile construction of N-N atropisomers and further expands the range of of N-N axially chiral derivatives. Additionally, under the conditions of electrocatalysis, the desired N-N axially chiral products were also successfully achieved with good to excellent efficiencies and enantioselectivities.
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Affiliation(s)
- Tong Li
- College of Chemistry, Zhengzhou University, Zhengzhou, 450001, P. R. China
| | - Linlin Shi
- College of Chemistry, Zhengzhou University, Zhengzhou, 450001, P. R. China
| | - Xinhai Wang
- College of Chemistry, Zhengzhou University, Zhengzhou, 450001, P. R. China
| | - Chen Yang
- College of Chemistry, Zhengzhou University, Zhengzhou, 450001, P. R. China
| | - Dandan Yang
- College of Chemistry, Zhengzhou University, Zhengzhou, 450001, P. R. China.
| | - Mao-Ping Song
- College of Chemistry, Zhengzhou University, Zhengzhou, 450001, P. R. China
| | - Jun-Long Niu
- College of Chemistry, Zhengzhou University, Zhengzhou, 450001, P. R. China.
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6
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Lanman BA, Parsons AT, Zech SG. Addressing Atropisomerism in the Development of Sotorasib, a Covalent Inhibitor of KRAS G12C: Structural, Analytical, and Synthetic Considerations. Acc Chem Res 2022; 55:2892-2903. [PMID: 36178208 PMCID: PMC9583618 DOI: 10.1021/acs.accounts.2c00479] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Nearly a century after its first description, configurationally stable axial chirality remains a rare feature in marketed drugs. In the development of the KRASG12C inhibitor sotorasib (LUMAKRAS/LUMYKRAS), an axially chiral biaryl moiety proved a critical structural element in engaging a "cryptic" protein binding pocket and enhancing inhibitor potency. Restricted rotation about this axis of chirality gave rise to configurationally stable atropisomers that demonstrated a 10-fold difference in potency. The decision to develop sotorasib as a single-atropisomer drug gave rise to a range of analytical and synthetic challenges, whose resolution we review here.Assessing the configurational stability of differentially substituted biaryl units in early inhibitor candidates represented the first challenge to be overcome, as differing atropisomer stability profiles called for differing development strategies (e.g., as rapidly equilibrating rotamers vs as single atropisomers). We relied on a range of NMR, HPLC, and computational methods to assess atropisomer stability. Here, we describe the various variable-temperature NMR, time-course NMR, and chiral HPLC approaches used to assess the configurational stability of axially chiral bonds displaying a range of rotational barriers.As optimal engagement of the "cryptic" pocket of KRASG12C was ultimately achieved with a configurationally stable atropisomeric linkage, the second challenge to be overcome entailed preparing the preferred (M)-atropisomer of sotorasib on industrial scale. This synthetic challenge centered on the large-scale synthesis of an atropisomerically pure building block comprising the central azaquinazolinone and pyridine rings of sotorasib. We examined a range of strategies to prepare this compound as a single atropisomer: asymmetric catalysis, chiral chromatographic purification, and classical resolution. Although chiral liquid and simulated moving bed chromatography provided expedient access to initial multikilo supplies of this key intermediate, a classical resolution process was ultimately developed that proved significantly more efficient on metric-ton scale. To avoid discarding half of the material from this resolution, this process was subsequently refined to enable thermal recycling of the undesired atropisomer, providing an even more efficient commercial process that proved both robust and green.While the preparation of sotorasib as a single atropisomer significantly increased both the analytical and synthetic complexity of its development, the axially chiral biaryl linkage that gave rise to the atropisomerism of sotorasib proved a key design element in optimizing sotorasib's binding to KRASG12C. It is hoped that this review will help in outlining the range of analytical techniques and synthetic strategies that can be brought to bear in addressing the challenges posed by such axially chiral compounds and that this account may provide helpful guidelines for future efforts aimed at the development of such single atropisomer, axially chiral pharmaceutical agents.
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Affiliation(s)
- Brian A. Lanman
- †Department
of Medicinal Chemistry and §Lead Discovery and Characterization, Amgen Inc., One Amgen Center Drive, Thousand Oaks, California91320, United States,
| | - Andrew T. Parsons
- Department
of Process Development, Drug Substance Technologies, Amgen Inc., 360 Binney
Street, Cambridge, Massachusetts02142, United States
| | - Stephan G. Zech
- †Department
of Medicinal Chemistry and §Lead Discovery and Characterization, Amgen Inc., One Amgen Center Drive, Thousand Oaks, California91320, United States
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7
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Yang YD, Yang BB, Li L. A nonneglectable stereochemical factor in drug development: Atropisomerism. Chirality 2022; 34:1355-1370. [PMID: 35904531 DOI: 10.1002/chir.23497] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 07/09/2022] [Accepted: 07/11/2022] [Indexed: 11/07/2022]
Abstract
Chirality is one of the key factors affecting the medicinal efficacy of compounds. In addition to central chirality, sterically hindered chiral axes commonly appear in drugs and the resulting chirality is known as atropisomerism. With developments in medicinal chemistry, atropisomerism has attracted increasing attention. This review discusses the classification, biological activity, pharmacokinetics, toxicity and side effects of atropisomers, and can serve as a reference in the research and development of potential chiral drugs.
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Affiliation(s)
- Ya-Dong Yang
- Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation, Institute of Materia Medica, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Bei-Bei Yang
- Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation, Institute of Materia Medica, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Li Li
- Beijing Key Laboratory of Active Substances Discovery and Druggability Evaluation, Institute of Materia Medica, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
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8
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Xu Q, Zhang H, Ge FB, Wang XM, Zhang P, Lu CJ, Liu RR. Cu(I)-Catalyzed Asymmetric Arylation of Pyrroles with Diaryliodonium Salts toward the Synthesis of N-N Atropisomers. Org Lett 2022; 24:3138-3143. [PMID: 35452582 DOI: 10.1021/acs.orglett.2c00812] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We report herein that copper(I) catalysis using a bis(phosphine) dioxide ligand can catalyze the desymmetric C-H arylation of prochiral bipyrroles. More than 50 nitrogen-nitrogen atropisomers were achieved in good to excellent yields with excellent enantioselectivities (≤97% yield, ≤98% ee). The reaction proceeds under mild conditions with good functional group compatibility on arenes and diaryliodonium salts. Moreover, this principle enables iterative arylation of the bipyrroles to enantioselectively arylate different positions during the catalysis of copper.
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Affiliation(s)
- Qi Xu
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, P. R. China
| | - Huan Zhang
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, P. R. China
| | - Fang-Bei Ge
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, P. R. China
| | - Xiao-Mei Wang
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, P. R. China
| | - Peng Zhang
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, P. R. China
| | - Chuan-Jun Lu
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, P. R. China
| | - Ren-Rong Liu
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, P. R. China
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9
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Gao Y, Wang LY, Zhang T, Yang BM, Zhao Y. Atroposelective Synthesis of 1,1'-Bipyrroles Bearing a Chiral N-N Axis: Chiral Phosphoric Acid Catalysis with Lewis Acid Induced Enantiodivergence. Angew Chem Int Ed Engl 2022; 61:e202200371. [PMID: 35174596 DOI: 10.1002/anie.202200371] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Indexed: 12/26/2022]
Abstract
We present herein a highly efficient atroposelective synthesis of axially chiral 1,1'-bipyrroles bearing an N-N linkage from simple hydrazine and 1,4-diones. Further product derivatizations led to axially chiral bifunctional compounds with high potential in asymmetric catalysis. For this chrial phosphoric acid (CPA)-catalyzed double Paal-Knorr reaction, an intriguing Fe(OTf)3 -induced enantiodivergence was also observed.
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Affiliation(s)
- Yaru Gao
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou, 350207, China.,Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Republic of Singapore
| | - Luo-Yu Wang
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou, 350207, China.,Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Republic of Singapore
| | - Tao Zhang
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Republic of Singapore
| | - Bin-Miao Yang
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou, 350207, China
| | - Yu Zhao
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou, 350207, China.,Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Republic of Singapore
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10
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Gao Y, Wang L, Zhang T, Yang B, Zhao Y. Atroposelective Synthesis of 1,1′‐Bipyrroles Bearing a Chiral N−N Axis: Chiral Phosphoric Acid Catalysis with Lewis Acid Induced Enantiodivergence. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202200371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Yaru Gao
- Joint School of National University of Singapore and Tianjin University International Campus of Tianjin University Binhai New City, Fuzhou 350207 China
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Republic of Singapore
| | - Luo‐Yu Wang
- Joint School of National University of Singapore and Tianjin University International Campus of Tianjin University Binhai New City, Fuzhou 350207 China
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Republic of Singapore
| | - Tao Zhang
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Republic of Singapore
| | - Bin‐Miao Yang
- Joint School of National University of Singapore and Tianjin University International Campus of Tianjin University Binhai New City, Fuzhou 350207 China
| | - Yu Zhao
- Joint School of National University of Singapore and Tianjin University International Campus of Tianjin University Binhai New City, Fuzhou 350207 China
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Republic of Singapore
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11
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Tabey A, Vemuri PY, Patureau FW. Cross-dehydrogenative N-N couplings. Chem Sci 2021; 12:14343-14352. [PMID: 34880984 PMCID: PMC8580018 DOI: 10.1039/d1sc03851f] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 09/10/2021] [Indexed: 11/21/2022] Open
Abstract
The relatively high electronegativity of nitrogen makes N-N bond forming cross-coupling reactions particularly difficult, especially in an intermolecular fashion. The challenge increases even further when considering the case of dehydrogenative N-N coupling reactions, which are advantageous in terms of step and atom economy, but introduce the problem of the oxidant in order to become thermodynamically feasible. Indeed, the oxidizing system must be designed to activate the target N-H bonds, while at the same time avoid undesired N-N homocoupling as well as C-N and C-C coupled side products. Thus, preciously few intermolecular hetero N-N cross-dehydrogenative couplings exist, in spite of the central importance of N-N bonds in organic chemistry. This review aims at analyzing these few rare cases and provides a perspective for future developments.
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Affiliation(s)
- Alexis Tabey
- Institute of Organic Chemistry, RWTH Aachen University Landoltweg 1 52074 Aachen Germany
| | - Pooja Y Vemuri
- Institute of Organic Chemistry, RWTH Aachen University Landoltweg 1 52074 Aachen Germany
| | - Frederic W Patureau
- Institute of Organic Chemistry, RWTH Aachen University Landoltweg 1 52074 Aachen Germany
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12
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Wang XM, Zhang P, Xu Q, Guo CQ, Zhang DB, Lu CJ, Liu RR. Enantioselective Synthesis of Nitrogen-Nitrogen Biaryl Atropisomers via Copper-Catalyzed Friedel-Crafts Alkylation Reaction. J Am Chem Soc 2021; 143:15005-15010. [PMID: 34496212 DOI: 10.1021/jacs.1c07741] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Nitrogen-nitrogen bonds containing motifs are ubiquitous in natural products and bioactive compounds. However, the atropisomerism arising from a restricted rotation around an N-N bond is largely overlooked. Here, we describe a method to access the first enantioselective synthesis of N-N biaryl atropisomers via a Cu-bisoxazoline-catalyzed Friedel-Crafts alkylation reaction. A wide range of axially chiral N-N bisazaheterocycle compounds were efficiently prepared in high yields with excellent enantioselectivities via desymmetrization and kinetic resolution. Heating experiments showed that the axially chiral bisazaheterocycle products have high rotational barriers.
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Affiliation(s)
- Xiao-Mei Wang
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao, Shandong 266071, China
| | - Peng Zhang
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao, Shandong 266071, China
| | - Qi Xu
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao, Shandong 266071, China
| | - Chang-Qiu Guo
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao, Shandong 266071, China
| | - De-Bing Zhang
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao, Shandong 266071, China
| | - Chuan-Jun Lu
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao, Shandong 266071, China
| | - Ren-Rong Liu
- College of Chemistry and Chemical Engineering, Qingdao University, Qingdao, Shandong 266071, China
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