A masked diboron in Cu-catalysed borylation reaction: highly regioselective formal hydroboration of alkynes for synthesis of branched alkenylboronsf

摘要

The use of a masked diboron as a boron source in the presence of a Cu-N-heterocyclic carbene (NHC) catalyst enables alkyl-, aryl-, heteroatom- and sityl-substituted terminal alkynes to undergo α-selective formal hydroboration to give diverse branched alkenylboron compounds exclusively. Synthetic potential of this a-selective hydroboration has been demonstrated by total synthesis of pharmaceuticalty significant bexarotene and LG100268.