Peptides pyridylalanine

Access to peptide mimetics and enzyme inhibitors was accomplished by the construction of pyridylalanine derivatives [139], Once incorporated into peptides, the resultant structure was capable of coordinating to cations. The desired amino acid 397 was prepared from 396 by a Heck reaction using an acrylic acid ester followed by hydrogenolysis. This species could then be incorporated into the desired mimetic system 398 that was capable of complexation with europium ions. 

At almost the same time. Miller et al. published a communication on pyridylalanine (Pal)-peptide 45 catalyzed enantioselective allenoate additions to A-acylimines 46 with moderate to good yields with high enantioselectivities (Scheme 1.21)." ... 

Miller and coworkers have performed kinetic studies on a pyridylalanine-peptide catalyzed enantioselective coupling of allenoates 16 and N-acyl imines 17 to investigate the mechanism of the aza-MBH reaction [20]. In the catalytic cycle of a typical MBH/aza-MBH reaction, the proton transfer step or C-C bond formation is often considered as the rate-determining step. However, through mechanistic... 

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