Carbanion-induced base-catalyzed synthesis of unsymmetrical biaryls from suitably functionalized, 2H-pyran-2-ones through ring-transformation reactions

A synthesis of unsymmetrical highly functionalized biaryls with an amino substituent juxtaposed with two nitrile groups in one of the Phenyl rings is delineated and illustrated by the carbanion-induced ring-transformation of 6-aryl-4-methylsulfanyl-2H-pyran-2-one-3-carbonitrile (1) and 4-sec-amino-6-aryl-2H-pyran-2-one-3-carbonitrile (2) to 2-amino-4-aryl-6-methylsulfanyl-1,3-benzodinitrile (3) and 2-amino-6-sec-amino-4-aryl-1,3-benzodinitrile (4) using malononitrile as it source of the carbanion, in moderate yield. (C) 2001 Elsevier Science Ltd. All rights reserved.