Copper-catalyzed gamma-selective and stereospecific substitution reaction of allylic carbonates with diboron: efficient route to chiral allylboron compounds.

A copper-catalyzed gamma-selective and stereospecific substitution reaction of allylic carbonates with a diboron reagent affording allylboron compounds is described. Boryl group was selectively introduced at the gamma-position of the leaving carbonate group. Functionalized allylboronates that have an acetal, ester, or isolated alkene were prepared. The reaction of optically active allylic carbonates underwent complete alpha-to-gamma chirality transfer with anti-stereochemistry to produce optically active allylboronates having a boron-substituted stereogenic center.