title: One-pot regioselective synthesis of meta-terphenyls via [3 + 3] annulation of nitroallylic acetates with alkylidenemalononitriles.
abstract: A highly efficient one-pot method has been developed for the synthesis of meta-terphenyls via a regioselective [3 + 3] annulation-elimination sequence involving Morita-Baylis-Hillman (MBH) acetates of nitroalkenes and alkylidenemalononitriles. The reaction takes place in a regioselective manner under mild conditions (Et3N, room temperature) to afford a wide variety of meta-terphenyls bearing aryl, heteroaryl and styrenyl groups. This novel [3 + 3] annulation takes advantage of the 1,3-bielectrophilic character of MBH acetates and 1,3-binucleophilic character of alkylidenemalononitriles and proceeds in a cascade fashion comprising an SN2' substitution, intramolecular 6-endo-trig Michael addition and double elimination. Representative synthetic transformations of the products, for instance, to meta-terphenyl derived isoindolinones have also been demonstrated.
authors.affiliation: Department of Chemistry, Indian Institute of Technology , Bombay, Mumbai, Maharashtra 400 076, India.
authors.forename: Elumalai
authors.initials: E
authors.lastname: Gopi
authors.forename: Irishi N N
authors.initials: IN
authors.lastname: Namboothiri