title: Reversal of Selectivity in C3-Allylation and Formal [3 + 2]-Cycloaddition of Spiro-epoxyoxindole: Unified Synthesis of Spiro-furanooxindole, (±)-N-Methylcoerulescine, (±)-Physovenine, and 3a-Allylhexahydropyrrolo[2,3-b]indole.
abstract: An effective Lewis acid catalyzed regioselective C3-allylation and a formal [3 + 2]-annulation reaction of spiro-epoxyoxindoles have been developed and can be accessed simply by changing the reaction conditions. This method has been successfully employed for the synthesis of spiro(pyrrolidinyloxindole), 3a-allylhexahydropyrrolo[2,3-b]indole, and furanoindoline.
authors.affiliation: Centre of Biomedical Research, Sanjay Gandhi Post-Graduate Institute of Medical Sciences Campus , Raebareli Road, Lucknow 226014, India.
authors.forename: Saumen
authors.identifier: 0000-0003-0303-4647
authors.initials: S
authors.lastname: Hajra
authors.affiliation: Centre of Biomedical Research, Sanjay Gandhi Post-Graduate Institute of Medical Sciences Campus , Raebareli Road, Lucknow 226014, India.
authors.forename: Sayan
authors.initials: S
authors.lastname: Roy
authors.affiliation: Centre of Biomedical Research, Sanjay Gandhi Post-Graduate Institute of Medical Sciences Campus , Raebareli Road, Lucknow 226014, India.|Department of Chemistry, Indian Institute of Technology Kharagpur , Kharagpur 721302, India.
authors.forename: Subrata
authors.initials: S
authors.lastname: Maity