{"title":"Single Photocatalytic Hydrosilylation of Alkenes for the Synthesis of Bis(silyl) and Silaboryl Alkanes.","authors":"Yuki Nagashima, Mone Suzuki, Asuha Shimose, Ryo Arai, Ken Tanaka, Masanobu Uchiyama","doi":"10.1021/jacsau.5c00831","DOIUrl":null,"url":null,"abstract":"<p><p>Bis-(silyl) and silaboryl alkanes are of interest as bioactive compounds and highly functionalized synthetic building blocks, but conventional hydrosilylation reactions lack generality and/or selectivity for synthesizing multielement-containing alkanes. Here, we present a versatile photoactivated hydrosilylation reaction of silicon- or boron-containing alkenes using silylborane as a silyl radical source to construct bis-(silyl) or silaboryl alkanes. This method employs a single phenothiazine-based photocatalyst and does not require conventional transition-metal or hydrogen-atom-transfer (HAT) catalysts or cocatalysts. Consequently, it has high generality, including alkenes bearing acid/base-sensitive groups, and provides high chemo-/regio-selectivity, overcoming the limitations of existing methods. This methodology also enables cyclizative functionalization of dienes and arylsilylation of boryl alkenes, and we show that the obtained multielement-containing alkanes are useful synthetic building blocks. Mechanistic studies uncovered a novel photoactivation mechanism, in which the phenothiazine catalyst directly facilitates Si-B bond cleavage in the triplet state, in contrast to conventional redox or HAT mechanisms, enabling radical hydrosilylation with a broad scope of alkenes.</p>","PeriodicalId":94060,"journal":{"name":"JACS Au","volume":"5 9","pages":"4481-4490"},"PeriodicalIF":8.7000,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12458007/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"JACS Au","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1021/jacsau.5c00831","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/9/22 0:00:00","PubModel":"eCollection","JCR":"Q1","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Bis-(silyl) and silaboryl alkanes are of interest as bioactive compounds and highly functionalized synthetic building blocks, but conventional hydrosilylation reactions lack generality and/or selectivity for synthesizing multielement-containing alkanes. Here, we present a versatile photoactivated hydrosilylation reaction of silicon- or boron-containing alkenes using silylborane as a silyl radical source to construct bis-(silyl) or silaboryl alkanes. This method employs a single phenothiazine-based photocatalyst and does not require conventional transition-metal or hydrogen-atom-transfer (HAT) catalysts or cocatalysts. Consequently, it has high generality, including alkenes bearing acid/base-sensitive groups, and provides high chemo-/regio-selectivity, overcoming the limitations of existing methods. This methodology also enables cyclizative functionalization of dienes and arylsilylation of boryl alkenes, and we show that the obtained multielement-containing alkanes are useful synthetic building blocks. Mechanistic studies uncovered a novel photoactivation mechanism, in which the phenothiazine catalyst directly facilitates Si-B bond cleavage in the triplet state, in contrast to conventional redox or HAT mechanisms, enabling radical hydrosilylation with a broad scope of alkenes.