A. S.  Paraskar and Sudalai, A., ?Co-catalyzed reductive cyclization of azido and cyano substituted alpha,beta-unsaturated esters with NaBH4: enantioselective synthesis of (R)-baclofen and (R)-rolipram?, Tetrahedron, vol. 62, no. 20, pp. 4907-4916, 2006.