An Olefinic 1,2‐Boryl‐Migration Enabled by Radical Addition: Construction ofgem‐Bis(boryl)alkanes

• DOI: 10.1002/ange.201903721
• Publication Date: 2019-05-06T20:43:19Z
• Authors: Binlin Zhao; Zexian Li; Yixiao Wu; Yandong Wang; Jiasheng Qian; Yu Yuan; Zhuangzhi Shi
• Keywords: Radical ion; Cationic polymerization

Abstract A series of in situ formed alkenyl diboronate complexes from Grignard reagents (commercially available or prepared bromides and Mg) with B 2 Pin (bis(pinacolato)diboron) react diverse alkyl halides by a Ru photocatalyst to give various gem‐bis(boryl)alkanes. Alkyl radicals add efficiently the complexes, adduct radical anions undergo radical‐polar crossover, specifically, 1,2‐boryl‐anion shift boron α‐carbon sp center. This transformation shows good functional‐group compatibility can serve as powerful synthetic tool for late‐stage functionalization complex compounds. Measurements quantum yield reveal that radical‐chain mechanism is operative which diboronates acts reductive quencher excited state photocatalyst.