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Three distinct procedures for obtaining the effective Gibbs energies of activation from computed energies for a reaction involving multiple reactant-state (RS) and transition-state (TS) conformers are shown to be equivalent. If Boltzmann-weighted average Gibbs energies for RS and TS are evaluated, then the Gibbs energy contribution from entropy of mixing of both RS and TS conformers must also be included in order to obtain the correct value for the effective Gibbs energy of activation. Application to a solvolytic reaction of 4,4’-dimethoxybenzhydrylpyridinium cation, which is shown to satisfy the Curtin-Hammett principle with rapid interconversion of RS conformers, demonstrates the use of each procedure for evaluation of the effective Gibbs energy of activation.

Two methods are presented for kinetic resolutions of compounds containing ester and sulfoxide functionalities (sulfinylalkanoates). In the first a crude lipase preparation from Pseudomonas sp. (K10) mediates enantioselective hydrolysis of these esters in an aqueous environment. The second method uses the same lipase preparation to promote enantioselective transestesterifications with alcohols in hexane

A chemoenzymatic approach for the synthesis of homoazasugars is described, utilizing an aldolase to catalyze the key asymmetric aldol addition reaction. This approach is illustrated by the synthesis of β-D-homomannonojirimycin (11) using D-fructose diphosphate (FDP) aldolase.

The one-pot, microwave-assisted synthesis of 5-thia-4b,10-diaza-indeno[2,1-a]indene-5,5-dioxide (6) and 10H-11-thia-5,10a-diaza-benzo[b]fluorene-11,11-dioxide (7) from 1,2-phenylenediamine and 2-aminobenzylamine, respectively, is described. Generation of a sulfonamide through reaction of the appropriate diamine with 2-cyanobenzenesulfonyl chloride is followed by a multistep intramolecular transformation and subsequent elimination of ammonia to provide the corresponding tetracycle in good yield.

Biocatalytic resolutions of methyl sulfinylacetates fford sulfoxides (R)-( 1 ) - ( 6 ) in very high optical yields; the products have been used in a systematic study of the “SPAC” reaction, an asymmetric synthesis of γ-hydroxy-α,β-unsaturated esters.