A copper(II)-catalyzed borylation of alkyl halides with bis(pinacolato)diboron (B2pin2) has been developed, which can be carried out in air, providing a wide range of primary, secondary, and some tertiary alkylboronates in high yields. A variety of functional groups are tolerated and the protocol is also applicable to unactivated alkyl chlorides (including 1,1- and 1,2-dichlorides). Preliminary mechanistic
Catalytic Boration of Alkyl Halides with Borane without Hydrodehalogenation Enabled by Titanium Catalyst
作者:Xianjin Wang、Penglei Cui、Chungu Xia、Lipeng Wu
DOI:10.1002/anie.202100569
日期:2021.5.25
titanium‐catalyzed boration of alkyl (pseudo)halides (alkyl‐X, X=I, Br, Cl, OMs) with borane (HBpin, HBcat) is reported. The use of titanium catalyst can successfully suppress the undesired hydrodehalogenation products that prevail using other transition‐metal catalysts. A series of synthetically useful alkyl boronate esters are readily obtained from various (primary, secondary, and tertiary) alkyl electrophiles,
A one-step hydroformylation of mixtures of internal and terminalolefins yielding terminalaldehydes without the need for carbon monoxide has been developed. Treatment of the olefin mixtures with Rh catalysts and pinacolborane leads to isomerization and hydroboration in one step. Homologation and subsequent oxidation regiospecifically afford the terminalaldehyde. Good overall yields are obtained for
Photo-induced radical borylation of hemiacetals via C–C bond cleavage
作者:Qianyi Liu、Jianning Zhang、Lei Zhang、Fanyang Mo
DOI:10.1016/j.tet.2020.131867
日期:2021.1
In this study, we reported a photo-induced radical borylation of hemiacetal derivatives via C–Cbondcleavage. This transformation can be realized under mild conditions with simple reaction settings and irradiation of visible light. A series of substrates, including both cyclic and linear hemiacetal derivatives, were effectively transformed to the borylation product in moderate to good yields. Finally