Microwave directed metal-free regiodivergent synthesis of 1,2-teraryls and study of supramolecular interactions

Abstract

A microwave directed, simple and efficient synthesis of 3′-amino-5′-(sec.amino)-[1,1′:2′,1′′-teraryl]-4′-carbonitriles has been delineated through ring transformation reaction of 6-aryl-2-oxo-4-sec.amino-2H-pyran-3-carbonitriles by benzyl cyanide under basic conditions. Reaction of 6-aryl-4-sec.amino-2-oxo-2H-pyran-3-carbonitriles and benzyl cyanide in DMSO and KOH as a base at 15 °C provides (2E,4E)-5-aryl-6-oxo-6-phenyl-3-sec.amino-hexa-2,4-dienenitriles. Reaction of 6-phenyl-4-(piperidin-1-yl)-2-oxo-2H-pyran-3-carbonitrile and benzyl cyanide in DMF and sodamide at 100 °C provides 1,5-diphenyl-3-(piperidin-1-yl)cyclopenta-2,4-diene-1,2-dicarbonitrile. Use of microwave irradiation diverts the regioselectivity and changes the course of reaction and 1,2-teraryls was isolated. The structure of one of the compound was confirmed by single crystal X-ray and the nature of weak interactions in the compound has been addressed using ab initio, atoms in molecules (AIM) and Hirshfeld surface analysis.