Cobalt-Catalyzed Hydroboration of Terminal and Internal Alkynes
作者:María J. González、Felix Bauer、Bernhard Breit
DOI:10.1021/acs.orglett.1c02854
日期:2021.11.5
A novel methodology to access synthetically versatile vinylboronic esters through a ligand-controlled cobalt-catalyzed hydroboration of terminal and internalalkynes is reported. The approach relies on the in situ reduction of Co(II) by H-BPin in the presence of bisphosphine ligands generating catalytically active Co(I) hydride complexes. This procedure avoids the use of stoichiometric amounts of base
Lithium-promoted hydroboration of alkynes and alkenes using commercially available hexamethyldisilazane lithium as a precatalyst and HBpin as a hydride source has been developed. This method will be appealing for organic synthesis because of its remarkable substrate tolerance and good yields. Mechanistic studies revealed that the hydroboration proceeds through the in situ-formed BH3 species, which