Michael addition reactions between various nucleophilic glycine equivalents and (S,E)-1-enoyl-5-oxo-N-phenylpyrrolidine-2-carboxamide, an optimal type of chiral Michael acceptor in the asymmetric synthesis of β-phenyl pyroglutamic acid and related compounds

Challenges and Strategies for Synthesizing Glutamyl Hydrazide Containing Peptides

Herein, we detail several specific challenges that hinder the effective synthesis of glutamyl hydrazide containing peptides, and we describe a synthetic strategy to work around these challenges. Glutamyl hydrazide is an unnatural amino acid residue that bears an acyl hydrazide functional group on its side chain. This family of compounds has the potential to provide potent and selective inhibitor molecules for several families of enzymes. During peptide synthesis, however, these side chains—even in protected form—can derail the synthesis by initiating undesired side reactions. Avoiding these side reactions is critical for enabling effective access to this family of compounds.

A ferrocenyl-DHIPOH/Cu(OAc)2 complex for diastereo- and enantioselective catalysis of the 1,4-addition of glycine derivatives to alkylidene malonates

A planar chiral ferrocene derivative Fc-DHIPOH served as an excellent N,O- chiral ligand for asymmetric copper catalyzed 1,4-addition of glycine derivatives to alkylidene malonates. The corresponding 1,4-adducts were obtained in high yields with excellent enantioselectivities up to 95% ee.