Lewis acid catalysis: catalytic hydroboration of alkynes initiated by Piers' borane
作者:Mirco Fleige、Juri Möbus、Thorsten vom Stein、Frank Glorius、Douglas W. Stephan
DOI:10.1039/c6cc05360b
日期:——
Terminal and internal alkynes are efficiently hydroborated to (E)-alkenyl pinacol boronic esters with excellent yields and selectivities using Piers' borane, (HB(C6F5)2) as a pre-catalyst for the dissymmetrically gem-diborylated catalyst of the form RCH2CR′(Bpin)(B(C6F5)2).
Ligand-enabled stereodivergence in nickel-catalyzed regioselective hydroboration of internal allenes
作者:Xiaoxu Yang、Chunchen Yuan、Shaozhong Ge
DOI:10.1016/j.chempr.2022.10.003
日期:2023.1
extremely rare. Herein, we demonstrate that such stereodivergence can be achieved for nickel-catalyzed hydroboration of internal allenes, which enables convenient synthesis of both stereoisomers of trisubstituted alkenylboronates from the same starting reagents. Mechanistic studies reveal that these nickel-catalyzedallene hydroboration reactions do not follow conventional hydrometallation or borylmetallation