Chiral Aminated α-Methylenebenzocycloalkenes from o-Bromoaryl Aldehydes and Ketones

Abstract

Chiral tert-butylsulfinyl imines 3, which are easily prepared from the corresponding bromo carbonyl compounds 1 and tert-butanesulfinamide (2), undergo a diastereoselective allylation by using indium metal and allyl bromide to give the corresponding homoallyl sulfinylamines 4. Treatment of compounds 4 with a catalytic amount of palladium acetate and triphenylphosphane gives exo-methylene-substitutedsulfinylamino)benzocycloalkenes 5 (five- to seven-membered rings) that are easily deprotected with hydrochloric acid to give chiral primary amines 6.