title: New types of reactivity of α,β-unsaturated N,N-dimethylhydrazones: chemodivergent diastereoselective synthesis of functionalized tetrahydroquinolines and hexahydropyrrolo[3,2-b]indoles.
abstract: The indium trichloride-catalyzed reaction between aromatic imines and α,β-unsaturated N,N-dimethylhydrazones in acetonitrile afforded 1,2,3,4-tetrahydroquinolines bearing a hydrazone function at C4 through a one-pot diastereoselective domino process that involves the formation of two C-C bonds and the controlled generation of two stereocenters, one of which is quaternary. This reaction constitutes the first example of an α,β-unsaturated dimethylhydrazone that behaves as a dienophile in a hetero Diels-Alder reaction. The related reaction between anilines, aromatic aldehydes, and methacrolein dimethylhydrazone in CHCl(3) with BF(3)⋅Et(2)O as catalyst afforded polysubstituted 1,2,3,3a,4,8b-hexahydropyrrolo[3,2-b]indoles as major products through a fully diastereoselective ABB'C four-component domino process that generates two cycles, three stereocenters, two C-C bonds, and two C-N bonds in a single operation.
authors.affiliation: Departmento de Química Orgánica y Farmacéutica, Universidad Complutense, Facultad de Farmacia, 28040 Madrid, Spain.
authors.forename: Vellaisamy
authors.initials: V
authors.lastname: Sridharan
authors.forename: Pascual
authors.initials: P
authors.lastname: Ribelles
authors.forename: Verónica
authors.initials: V
authors.lastname: Estévez
authors.forename: Mercedes
authors.initials: M
authors.lastname: Villacampa
authors.forename: M Teresa
authors.initials: MT
authors.lastname: Ramos
authors.forename: Paramasivan T
authors.initials: PT
authors.lastname: Perumal
authors.forename: J Carlos
authors.initials: JC
authors.lastname: Menéndez