Picolinoxy group, a new leaving group for anti SN2' selective allylic substitution with aryl anions based on Grignard reagents.

The picolinoxy group was found to be an extremely powerful leaving group for allylic substitution with aryl nucleophiles derived from ArMgBr and CuBr•Me2S. The substitution proceeds with anti SN2′ pathway and with high chirality transfer. The electron-withdrawing effect of the pyridyl group and chelation to MgBr2 are likely the origin of success. Results suggesting these effects were obtained.