Access to Cyclic Amino Boronates via Rhodium-Catalyzed Functionalization of Alkyl MIDA Boronates

Herein,
we describe the rhodium-catalyzed C–H amination
reaction of 1,2-boryl sulfamate esters derived from amphoteric α-boryl
aldehydes. Depending on the substitution pattern of the boryl sulfamate
ester, a diverse range of five- or six-membered ring heterocycles
are accessible using this transformation. The highly chemoselective
nature of the C–H functionalization reaction preserves the
alkyl boronate functional group, which enables the synthesis of B–C–N
and B–C–C–N motifs that are present in a number
of hydrolase inhibitors.