Copper-boryl mediated transfer hydrogenation of N-sulfonyl imines using methanol as the hydrogen donor

ABSTRACT B2Pin2-assisted copper-catalyzed transfer hydrogenation of aromatic sulfonylimines has been achieved, delivering a variety of aryl/heteroaryl sulfonamides in good to excellent yields under mild reaction conditions and with methanol as the hydrogen source. Mechanistic studies suggest that the reaction may proceed via a transient α-borylated intermediate, followed by protodeboration to afford the sulfonamide products.