Organocatalytic asymmetric allylic benzylborylation via fluoride-assisted catalytic generation of alpha-boryl carbanionic intermediates

Herein we describe the organocatalytic asymmetric allylic benzylborylation of racemic allyl fluorides with racemic alpha-silyl benzylboronic esters under Lewis-base catalysis. The catalytic protocol leverages the singular features of fluoride as unconventional leaving group, enabling the catalytic generation of reactive alpha-boryl carbanion species through fluoride-assisted desilylative activation. It allows the construction of a wide set of homoallylic benzylated organoboronates bearing two contiguous stereocenters in a regio-, diastereo-, and enantioselective fashion. In addition, the chiral boronate moiety installed in the final products serves as a synthetic lynchpin for stereospecific derivatizations to construct complex chemical architectures.