Anti‐Selective Borylstannylation of Alkynes with (o‐Phenylenediaminato)borylstannanes by a Radical Mechanism. (11th May 2022)

• Record Type: Journal Article
• Authors: Suzuki, Kensuke; Sugihara, Naoki; Nishimoto, Yoshihiro; Yasuda, Makoto
• Is Part Of: Angewandte Chemie. Volume 134:Number 27(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-05-11
• Subjects: Alkynes -- Boron -- Borylstannylation -- Radical Reactions -- Tin; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202201883
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: We have achieved the first anti ‐borylstannylation of alkynes by using ( o ‐phenylenediaminato)borylstannanes. This reaction afforded 1‐boryl‐2‐stannylalkenes with excellent regio‐ and stereoselectivity by a radical mechanism. This anti ‐addition manner is in sharp contrast to the syn ‐selectivity obtained during transition metal‐catalyzed borylstannylation. The mild radical conditions enabled a broad substrate scope, and various types of aromatic and aliphatic alkynes were applicable. The origin of regio‐ and stereoselectivity was elucidated by DFT calculation of the reaction mechanism. The application of the borylstannylation products to cross‐ or homocoupling reactions provided ready access to either triarylethenes or bisborylbutadienes. Abstract : The first anti ‐borylstannylation of alkynes has been achieved by a radical mechanism with (o‐phenylenediaminato)borylstannanes. This anti ‐addition manner is in contrast to the syn ‐selectivity in transition metal‐catalyzed borylstannylation. 1‐Boryl‐2‐stannylalkenes, which were applicable to sequential cross‐coupling, were obtained with excellent regio‐ and stereoselectivity. The mechanism was revealed by DFT studies.