Templates for Intramolecular O,N-Acyl Transfer via Cyclic Intermediates Derived from Mercury Derivatives of L-Cysteine: Progress toward a Mercury-Based Thiol Capture Strategy

Article abstract of DOI:10.1021/jo00277a022

A first study is reported of optimization of a template bridging an oxygen ester with mercury that facilitates intramolecular O,N-acyl transfer from a phenolic oxygen to the amino group of a cysteine residue that is functionalized at sulfur as an arylmercuri complex.Respective effective molarities (EM values) of 0.28, ca. 0.6, and 0.0 are observed for the following three arylmercuri complexes: methyl S-((4-acetoxy-6-phenoxathiinyl)mercuri)-L-cysteinate (9), methyl S-((5-acetoxy-1,3-dimethoxy-2-methyl-9-oxoxanth-4-yl)mercuri)-L-cysteinate (10), and methyl S-((4-acetoxydibenzofuran-6-yl)mercuri)-L-cysteinate (11).Syntheses of these compounds are reported, and the structural significance of the EM values for transition states of the acyl-transfer reactions is discussed.The observed reactivity pattern is consistent with a linear geometry at the mercury atom and a geometry about the forming C-N bond of other than the trans, anti relationship that has been observed for intermolecular acyl-transfer reactions.