Rapid access to Asp/Glu sidechain hydrazides as thioester precursors for peptide cyclization and glycosylation.

Head-to-sidechain macrocylic peptides, and neoglycopeptides, were readily prepared by site-specific amidation of aspartic and glutamic acid sidechain hydrazides. Hydrazides, serving as latent thioesters, were introduced through regioselective opening of the corresponding Nα-Fmoc protected anhydride precursors.

A 2-step synthesis of Combretastatin A-4 and derivatives as potent tubulin assembly inhibitors.

A series of combretastatin derivatives were designed and synthesised by a two-step stereoselective synthesis by use of Wittig olefination followed by Suzuki cross-coupling. Interestingly, all new compounds (2a-2i) showed potent cell-based antiproliferative activities in nanomolar concentrations. Among the compounds, 2a, 2b and 2e were the most active across three cancer cell lines.