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Wei Y, Xie XY, Liu J, Liu X, Zhang B, Chen XY, Li SJ, Lan Y, Hong K. Palladium-Catalyzed Cascade Heck Coupling and Allylboration of Iododiboron Compounds via Diboryl Radicals. Angew Chem Int Ed Engl 2024; 63:e202401050. [PMID: 38444397 DOI: 10.1002/anie.202401050] [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: 02/01/2024] [Revised: 03/01/2024] [Accepted: 03/06/2024] [Indexed: 03/07/2024]
Abstract
Geminal bis(boronates) are versatile synthetic building blocks in organic chemistry. The fact that they predominantly serve as nucleophiles in the previous reports, however, has restrained their synthetic potential. Herein we disclose the ambiphilic reactivity of α-halogenated geminal bis(boronates), of which the first catalytic utilization was accomplished by merging a formal Heck cross-coupling with a highly diastereoselective allylboration of aldehydes or imines, providing a new avenue for rapid assembly of polyfunctionalized boron-containing compounds. We demonstrated that this cascade reaction is highly efficient and compatible with various functional groups, and a wide range of heterocycles. In contrast to a classical Pd(0/II) scenario, mechanistic experiments and DFT calculations have provided strong evidence for a catalytic cycle involving Pd(I)/diboryl carbon radical intermediates.
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Affiliation(s)
- Yi Wei
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, 3663 N Zhongshan Road, Shanghai, 200062, China
| | - Xiao-Yu Xie
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, 3663 N Zhongshan Road, Shanghai, 200062, China
| | - Jiabin Liu
- Green Catalysis Center, and College of Chemistry, Zhengzhou University, Zhengzhou, Henan, 450001, China
| | - Xiaoxiao Liu
- Green Catalysis Center, and College of Chemistry, Zhengzhou University, Zhengzhou, Henan, 450001, China
| | - Bo Zhang
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, 3663 N Zhongshan Road, Shanghai, 200062, China
| | - Xin-Yi Chen
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, 3663 N Zhongshan Road, Shanghai, 200062, China
| | - Shi-Jun Li
- Green Catalysis Center, and College of Chemistry, Zhengzhou University, Zhengzhou, Henan, 450001, China
| | - Yu Lan
- Green Catalysis Center, and College of Chemistry, Zhengzhou University, Zhengzhou, Henan, 450001, China
- School of Chemistry and Chemical Engineering, and Chongqing Key Laboratory of Theoretical and Computational Chemistry, Chongqing University, Chongqing, 400030, China
| | - Kai Hong
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, 3663 N Zhongshan Road, Shanghai, 200062, China
- Shanghai Frontiers Science Center of Molecule Intelligent Syntheses, School of Chemistry and Molecular Engineering, East China Normal University, 3663 N Zhongshan Road, Shanghai, 200062, China
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Ning PF, Wei Y, Chen XY, Yang YF, Gao FC, Hong K. A General Method to Access Sterically Encumbered Geminal Bis(boronates) via Formal Umpolung Transformation of Terminal Diboron Compounds. Angew Chem Int Ed Engl 2024; 63:e202315232. [PMID: 38059757 DOI: 10.1002/anie.202315232] [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: 10/10/2023] [Revised: 11/30/2023] [Accepted: 12/01/2023] [Indexed: 12/08/2023]
Abstract
General methods for the preparation of geminal bis(boronates) are of great interest due to their widespread applications in organic synthesis. While the terminal gem-diboron compounds are readily accessible, the construction of the sterically encumbered, internal analogues has remained a prominent challenge. Herein, we report a formal umpolung strategy to access these valuable building blocks. The readily available 1,1-diborylalkanes were first converted into the corresponding α-halogenated derivatives, which then serve as electrophilic components, undergoing a formal substitution with a diverse array of nucleophiles to form a series of C-C, C-O, C-S, and C-N bonds. This protocol features good tolerance to steric hindrance and a wide variety of functional groups and heterocycles. Notably, this strategy can also be extended to the synthesis of diaryl and terminal gem-diboron compounds, therefore providing a general approach to various types of geminal bis(boronates).
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Affiliation(s)
- Peng-Fei Ning
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, 3663 N Zhongshan Road, Shanghai, 200062, China
| | - Yi Wei
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, 3663 N Zhongshan Road, Shanghai, 200062, China
| | - Xin-Yi Chen
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, 3663 N Zhongshan Road, Shanghai, 200062, China
| | - Yi-Fei Yang
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, 3663 N Zhongshan Road, Shanghai, 200062, China
| | - Feng-Chen Gao
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, 3663 N Zhongshan Road, Shanghai, 200062, China
| | - Kai Hong
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, 3663 N Zhongshan Road, Shanghai, 200062, China
- Shanghai Frontiers Science Center of Molecule Intelligent Syntheses, School of Chemistry and Molecular Engineering, East China Normal University, 3663 N Zhongshan Road, Shanghai, 200062, China
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Zähringer TJB, Wienhold M, Gilmour R, Kerzig C. Direct Observation of Triplet States in the Isomerization of Alkenylboronates by Energy Transfer Catalysis. J Am Chem Soc 2023; 145:21576-21586. [PMID: 37729087 DOI: 10.1021/jacs.3c07678] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
Alkenylboronates are versatile building blocks for stereocontrolled synthesis owing to the traceless nature of the boron group that can be leveraged to achieve highly selective geometric isomerization. Using thioxanthone as an inexpensive photocatalyst, the photoisomerization of these species continues to provide an expansive platform for stereodivergent synthesis, particularly in the construction of bioactive polyenes. Although mechanistic investigations are consistent with light-driven energy transfer, direct experimental evidence remains conspicuously absent. Herein, we report a rigorous mechanistic investigation using two widely used alkenylboronates alongside relevant reference compounds. Through the combination of irradiation experiments, transient absorption spectroscopic studies, kinetic modeling, and DFT calculations with all isomers of the model compounds, it has been possible to unequivocally detect and characterize the perpendicular triplet generated by energy transfer. Our results serve not only as a blueprint for mechanistic studies that are challenging with organic sensitizers, but these guidelines delineated have also enabled the development of more sustainable reaction conditions: for the first time, efficient organocatalytic isomerization under sunlight irradiation has become feasible.
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Affiliation(s)
- Till J B Zähringer
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Max Wienhold
- Organisch-Chemisches Institut,Westfälische Wilhelms-Universität Münster, Correnstraβe 36, 48149 Münster, Germany
| | - Ryan Gilmour
- Organisch-Chemisches Institut,Westfälische Wilhelms-Universität Münster, Correnstraβe 36, 48149 Münster, Germany
- Cells in Motion (CiM) Interfaculty Center, Röntgenstraβe 16, 48149 Münster, Germany
| | - Christoph Kerzig
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
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