Borylation of Alkynes under Base/Coinage Metal Catalysis: Some Recent Developments

Alkenylboranes have been vital reagents in modern synthetic organic chemistry, whose carbon–boron bond is transformable into a carbon–carbon bond stereoretentively to give such invaluable mutisubstituted alkenes as natural products, biologically active molecules, and functional materials. Introduction of a boryl moiety across a carbon–carbon triple bond of alkynes (borylation of alkynes) is one of the most direct and potent methods for synthesizing alkenylboranes, and this field has thus far experienced remarkable progress mainly with group 10 transition metal catalysts (Ni, Pd, Pt), which enables highly functionalized alkenylboranes to be constructed stereoselectively. On the other hand, much attention has recently been focused on the appealing catalysis of base (Fe, Co) and coinage (Cu, Ag, Au) metals toward the borylation of alkynes, which is summarized in this perspective.