in a stereoselective manner. The reaction proceeds through generation of an α‐imino rhodium carbene complex, nucleophilic addition of the sulfur atom of a thioester onto the carbenoid carbonatom, and subsequent intramolecular migration of the acyl groupfrom the sulfur atom to the imino nitrogen atom. The method is successfully applied to a ring‐expansion reaction of thiolactones, thus leading to
A series of novel peptide-based β-thiolactones were synthesized and assayed for cytotoxicity against several human cancer cell lines, where they showed greater activity than the corresponding β-lactones and β-lactams. Several of the β-thiolactones prepared showed strong inhibitory activity in vitro against human cathepsins B and L.
The controlled ring-opening polymerization of the β-thiolactone derived from N-Boc cysteine was achieved using N-Boc-L-cysteine methyl ester as the initiator in NMP at room temperature. The propagating end is the thiol group, which attacks the carbonyl to open the monomer ring by the C(═O)–S bond scission. A thiol–ene click reaction demonstrated the utility of the thiol group at the propagating terminal
S<sub>N</sub>2-Type Nucleophilic Opening of β-Thiolactones (Thietan-2-ones) as a Source of Thioacids for Coupling Reactions
作者:David Crich、Kasinath Sana
DOI:10.1021/jo9001728
日期:2009.5.1
3-arylthiopropionamides carrying various substituents in the 2-position. Alternatively, the trapping combination of an electron deficient aryl halide and an amine may be replaced by a 2,4-dinitrobenzenesulfonamide, resulting in the formation of the same products overall with the incorporation of the latent amine in the sulfonamide into the final amide product. In another embodiment, the thiocarboxylate intermediate
The ligation of sterically demanding peptidyl sites such as those involving Val–Val and Val–Pro linkages has proven to be extremely challenging with conventional NCL methods that rely on exogenous thiol additives. Herein, we report an efficient β-thiolactone-mediated additive-free NCL protocol that enables the establishment of these connections in good yield. The rapid NCL was followed by in situ desulfurization