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Tricyclic benzopyrans are medicinally important biologically active compounds. Synthesis of a series of tricyclic benzopyrans derivatives via N-Heterocyclic carbene (NHC) catalyzed annulation of enals to α-methylidenetetralones/chromanones is described. This reaction afforded the benzopyrans in high yield with aromatic as well as aliphatic enals.

An unexpected transformation of 1,6-diarylhexa-1,5-diene-3,4-diones (cinnamils) to 2,3,8-triaryl vinyl fulvenes via N-Heterocyclic Carbene (NHC) catalysis is reported. Mechanistic as well as synthetic novelty is the hallmark of this reaction.

Nucleophilic heterocyclic carbene (NHC)-catalyzed ­annulation strategy has been utilized for the efficient synthesis of styrenyl-substituted cyclopentenes from 2,4-dienones.

The facile synthesis of 1,3,4-trisubstituted cyclopentenes via homoenolate annulation of enals with heterocycle substituted chalcones is described.

A stereoselective Michael addition of homoenolate, generated from enals by nucleophilic heterocyclic carbene (NHC) catalysis, to beta-nitrostyrenes is reported for the first time. The products of this reaction obtained in good yields are of potential value in the synthesis of a variety of acyclic and heterocyclic compounds.

Homoenolate annulation of vinyl ketones led to the synthesis of dihydropyranones in contrast to cyclopentenes obtained by the homoenolate annulation of chalcones, another class of α,β-unsaturated ketones.

A nucleophilic heterocyclic carbene mediated homoenolate annulation of enals to aurone analogs leading to the efficient synthesis of cyclopentene-fused spirobenzofuran-3-ones is reported.

Homoenolate generated from alpha,beta-unsaturated aldehydes by NHC catalysis underwent facile addition to conjugated sulfonimines, generated in situ, and subsequent methanolysis to afford protected GABA derivatives stereoselectively and in high yields, thus constituting a novel pseudo four component reaction.