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New Types of Reactivity of α,β‐Unsaturated N , N ‐Dimethylhydrazones: Chemodivergent Diastereoselective Synthesis of Functionalized Tetrahydroquinolines and Hexahydropyrrolo[3,2‐ b ]indoles
Author(s) -
Sridharan Vellaisamy,
Ribelles Pascual,
Estévez Verónica,
Villacampa Mercedes,
Ramos M. Teresa,
Perumal Paramasivan T.,
Menéndez J. Carlos
Publication year - 2012
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201103562
Subject(s) - stereocenter , chemistry , hydrazone , medicinal chemistry , domino , acetonitrile , catalysis , stereochemistry , organic chemistry , enantioselective synthesis
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 CC 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 CC bonds, and two CN bonds in a single operation.