Diastereoselective synthesis of an argatroban intermediate, ethyl (2R,4R)-4-methylpipecolate, by means of a Mandyphos/rhodium complex-catalyzed hydrogenation
摘要:
The synthetic antithrombotic argatroban is a dipeptide between the nonproteogenic (2R,4R)-4-methyl-2-piperidine carboxylic acid and L-arginine, in turn bonded to a methyltetrahydroquinoline sulfonyl group. An extensive screening of transition metal-based complexes with different ligands was performed in order to identify the best catalyst for the diastereoselective hydrogenation of a suitable 4,5-dehydropiperidine precursor aimed toward a synthesis of the (2R,4R)-4-methyl piperidine moiety. (C) 2011 Elsevier Ltd. All rights reserved.