Copper(I)-Catalyzed Regio- and Stereoselective Silaboration of Terminal Allenes

Organic compounds bearing both silyl and boryl groups
are important
building blocks in organic synthesis because of the adequate reactivity
of the silyl and boryl groups and high stereospecificity in their
derivatization reactions. The difference in reactivity between the
silyl and boryl groups enables stepwise derivatization of these groups
to afford complex molecules. Here, we report the copper­(I)-catalyzed
silaboration of terminal allenes to produce multisubstituted allylic
boronates embedded with an alkenyl silane structure. The reaction
can proceed with a variety of allenes and silylboranes. Furthermore,
the silyl and boryl groups were successfully converted into other
functional groups, while retaining the stereochemistry of the alkene
moiety.