Copper-catalyzed regioselective <i>trans</i>-silaboration of internal arylalkynes with stereochemical switch to <i>cis</i>-addition mode
Toshimichi Ohmura, Yuta Takaoka, Michinori Suginome
Abstract
Copper-catalyzed silafunctionalization of alkynes using a silylboronic ester as a silicon source has recently progressed rapidly. Generally, the reaction affords a product with cis-stereoselectivity. We herein describe trans-selective 1,2-addition of silylboronic esters to internal arylalkynes, which was promoted efficiently by the CuOt-Bu/RCy2P/NaOt-Bu catalysts. Moreover, we report a stereochemical switch to cis-addition in the reactions of Me2(i-PrO)Si-B(pin) in hydrocarbon solvents including cyclohexane.
Topics & Concepts
RegioselectivityStereoselectivityCopperCatalysisChemistrySolventStereochemistryCombinatorial chemistryOrganic chemistryOrganoboron and organosilicon chemistryCatalytic Cross-Coupling ReactionsChemical Synthesis and Analysis