Study of Ground State Interactions of Enantiopure Chiral Quaternary Ammonium Salts and Amides, Nitroalkanes, Nitroalkenes, Esters, Heterocycles, Ketones and Fluoroamides.

Chiral phase-transfer catalysis provides high level of enantiocontrol, however no experimental data showed the interaction of catalysts and substrates. H NMR titration was carried out on Cinchona and Maruoka ammonium bromides vs. nitro, carbonyl, heterocycles, and N-F containing compounds.

Enantioselective Synthesis of 3,4-Dihydropyran-2-ones via Phase-Transfer-Catalyzed Addition-Cyclization of Acetylacetone to Cinnamic Thioesters.

Herein, we present the first example of synthesis of 3,4-dihydropyran-2-ones from cinnamic thioesters via a stereoselective phase-transfer-catalyzed domino Michael-cyclization reaction with acetylacetone. The reaction proceeded under the catalysis of -derived quaternary ammonium phenoxide that, in combination with inorganic bases, provided 3,4-dihydropyran-2-ones in yields of up to 93% and enantioselectivities of up to 88% enantiomeric excess.

First enantioselective synthesis of gingesulfonic acids and unequivocal determination of their absolute stereochemistry.

Herein we report the first organocatalysed enantioselective synthesis of gingesulfonic acids and shogasulfonic acids via a mild and convenient aminothiourea-catalysed conjugate addition of bisulfite to the olefin moiety of α,β-unsaturated carbonyls-a technology previously reported by us. A series of optically active naturally occurring sulfonic acids are prepared in their natural and unnatural configurations, and their absolute configurations are unequivocally confirmed by single crystal X-ray diffractometry.