ChemInform Abstract: Doubly Dearomatizing Intramolecular Coupling of a Nucleophilic and an Electrophilic Heterocycle.

Abstract

Pyridine derivatives R 0380Doubly Dearomatizing Intramolecular Coupling of a Nucleophilic and an Electrophilic Heterocycle. -Isonicotinamides, carrying N-furanylmethyl, N-pyrrolylalkyl or N-thiophenylmethyl substituents at nitrogen, e.g. compounds (I), (IV) and (VI), undergo cyclization induced by an electrophile such as triflic anhydride (II). Spirocyclic or doubly spirocyclic compounds (III) and (VIII) are obtained in which both the nucleophilic and electrophilic heterocycles are dearomatized. The intermediate oxonium ion derived from (VI) can be trapped by an external nucleophile such as triphenylmethanol (VII) to give compound (VIII). -(BRICE, H.; CLAYDEN*, J.; Chem. Commun. (Cambridge) 2009, 15, 1964-1966; Sch. Chem., Univ. Manchester, Manchester M13 9PL, UK; Eng.) -M. Paetzel 35-142