Stereoselective Direct Chlorination of Alkenyl MIDA Boronates: Divergent Synthesis of E and Z α-Chloroalkenyl Boronates

The individual molecules of alpha-chloroalkenyl boronates include both an electrophilic C-Cl bond and a nucleophilic C-B bond, which makes them intriguing organic synthons. Reported herein is a stereodivergent synthesis of both Eand Z alpha-chloroalkenyl N-methyliminodiacetyl (MIDA) boronates through the direct chlorination of alkenyl MIDA boronates using tBuOCl and PhSeCl reagents, respectively. Both reaction processes are stereospecific and the use of sp(3)-B MIDA boronate is the key contributor to the reactivity. The synthetic value of the boronate products was also demonstrated.