@article {43798,
	title = {Organocatalytic enantioselective vinylogous michael-aidoi cascade for the synthesis of spirocyclic compounds},
	journal = {Organic Letters},
	volume = {19},
	year = {2017},
	month = {AUG},
	pages = {4367-4370},
	type = {Article},
	abstract = {Enantioselective synthesis of pyrazolone-fused spirocyclohexenols by the secondary amine-catalyzed cascade reaction of alpha,beta-unsaturated aldehydes with alpha-arylidene pyrazolinones is reported. This formal [3 + 3] organocascade reaction proceeds through a vinylogous Michael-aldol sequence to furnish the spiroheterocycles with three stereocenters including an all-carbon quaternary center in good yields and selectivities. The catalytic generation of alpha,beta-unsaturated iminium ions from enals and tandem dienolate/enolate formation from pyrazolinones are the key for the success of this spiroannulation reaction.},
	doi = {10.1021/acs.orglett.7b02085},
	author = {Mondal, Santigopal and Mukherjee, Subrata and Yetra, Santhivardhana Reddy and Gonnade, Rajesh G. and Biju, Akkattu T.}
}
