Amino acids and amines have been used to catalyze three component hetero-domino Knoevenagel/Diels-Alder/epimerization reactions of readily available various precursor enones (1a-l), aldehydes (2a-p), and 1,3-indandione (3). The reaction provided excellent yields of highly substituted, symmetrical and nonsymmetrical spiro[cyclohexane-1,2'-indan]-1',3',4-triones (5) in a highly diastereoselective fashion with low to moderate enantioselectivity. The Knoevenagel condensation of arylaldehydes (2a-p) and 1,3-indandione (3) under organocatalysis provided arylidene-1,3-indandiones (17) in very good yields. We demonstrate for the first time amino acid- and amine-catalyzed epimerization reactions of trans-spiranes (6) to cis-spiranes (5). The mechanism of conversion of trans-spiranes (6) to cis-spiranes 5 was shown to proceed through a retro-Michael/Michael reaction rather than deprotonation/reprotonation by isolation of the morpholine enamine intermediate of cis-spirane (22). Prochiral cis-spiranes (5ab) and trans-spiranes (6ab) are excellent starting materials for the synthesis of benzoannelated centropolyquinanes. Under amino acid and amine catalysis, the topologically interesting dispirane 24 was prepared in moderate yields. Organocatalysis with pyrrolidine catalyzed a series of four reactions, namely the Michael/retro-Michael/Diels-Alder/epimerization reaction sequence to furnish cis-spirane 5ab in moderate yield from enone 1a and 1,3-indandione 3.

An enantiospecific approach to mayurone and thujopsenes, sesquiterpenes containing three contiguous quaternary carbon atoms, starting from (R)-carvone (8), is described. (S)-3,4,4-Trimethylcarvone (7), obtained from (R)-carvone, was transformed into the bicyclo[2.2.2]octanone 13 via regioselective intramolecular alkylation of the allyl bromide 11. Regioselective ozonolysis and Criegee fragmentation of the bicyclic ketone 13 furnished the keto ester 14. Reductive deoxygenation followed by one-carbon homologation transformed the keto ester 19 into the ester 6. Intramolecular cyclopropanation of the diazo ketone 25, derived from the acid 5, furnished (-)-dihydromayurone (4), thus constituting a formal enantiospecific synthesis of mayurone and thujopsenes.

His research focuses on the design and implementation of organocatalytic selective [3 + 2]-cycloadditions and organocatalytic asymmetric reactions for the synthesis of biologically important drugs and drug-like molecules.

The recent past has witnessed tremendous growth in the field of asymmetric synthesis through “asymmetric supramolecular organocatalysis (ASO)”. ASO emerges from many interactions between substrates and catalysts: namely substrate–catalyst, catalyst–catalyst and substrate–substrate interactions. As a result, ASO has come to be the fourth pillar of asymmetric catalysis. This review summarizes recent advances in the high‐yielding asymmetric synthesis of chiral compounds from functionally rich substrates with the aid of combinations of two or more organocatalysts working synergistically through relatively stable pre‐transition states. ASO not only assists in product formation from highly functionalized substrates with high rate/selectivity, but also sheds some light on understanding of the fundamental aspects of the pre‐transition state structures.

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