Lipase-catalyzed kinetic resolution of 3-phenyloxazolidin-2-one derivatives: Cascade O- and N-alkoxycarbonylations

Regio- and Enantioselective Construction of Tetrazole Hemiaminal Esters and Related Prodrugs via Biocatalytic Dynamic Kinetic Resolution

Enzyme-catalyzed dynamic kinetic resolution was applied to the one-pot regio- and enantioselective synthesis of 2,5-disubstituted tetrazole hemiaminal esters, among which 72% of the products were obtained in excellent enantiopurities (99% ees). Tunable stereoselectivity was achieved by using different types of enzymes during the synthesis of a key intermediate for a clinic drug candidate. Successful preparation of tetrazole ester prodrugs and high catalyst recyclability further demonstrated the potential practical application of this protocol.

Base-mediated synthesis of cyclic dithiocarbamates from 1-amino-3-chloropropan-2-ol derivatives and carbon disulfide

An efficient method for the preparation of six-membered cyclic dithiocarbamates is described, in which triethylamine effectively promotes the reaction of 1-amino-3-chloropropan-2-ol derivatives with carbon disulfide. On the basis of the experimental and theoretical studies, a reaction mechanism is proposed to explain the difference between the present reaction and our previously reported carbon dioxide fixation.

Catalytic Dealkylative Synthesis of Cyclic Carbamates and Ureas via Hydrogen Atom Transfer and Radical-Polar Crossover

Guided by the transition-metal hydrogen atom transfer and radical-polar crossover concepts, we developed a functional-group-tolerant and scalable method for the synthesis of cyclic carbamates and ureas, which are found in the structures of bioactive compounds. This method provides not only a common five-membered ring but also six-to-eight-membered ring products. The reaction proceeds through the intramolecular displacement of an alkylcobalt(IV) intermediate and dealkylation by 2,4,6-collidine; the activation energies of these steps were calculated by DFT.