Substituted piperidinyl glycinyl 2-cyano-4,5-methano pyrrolidines as potent and stable dipeptidyl peptidase IV inhibitors

Synthesis and structure–activity relationship of a series of substituted piperidinyl glycine 2-cyano-4,5-methano pyrroline DPP-IV inhibitors are described. Improvement of the inhibitory activity and chemical stability of this series of compounds was respectively achieved by the introduction of bulky groups at the 4-position and 1-position of the piperidinyl glycine, leading to a series of potent and stable DPP-IV inhibitors.