Ruthenium-catalyzed one-pot carbenoid N-H insertion reactions and diastereoselective synthesis of prolines.

Aryl- and aliphatic-substituted 3-hydroxyprolines and various other amino esters are conveniently prepared by [RuCl2(p-cymene)]2-catalyzed one-pot intramolecular and intermolecular carbenoid N-H insertion reactions, respectively, and the prolines are formed with high diastereoselectivities. The catalytic reactions are tolerant toward air/moisture, and the product yields are insensitive to the organic solvents used.