A metal-free direct trifluoromethylthiolation of sulfonium ylides with an electrophilic trifluoromethylthiolating reagent has been established, in which sulfonium salt or α-bromoacetic ester is employed as sulfonium ylide precursors. This trifluoromethylthiolation enables the straightforward construction of SCF3-substituted sulfonium ylides from a wide range of substrates, including ketones, esters
Enantioselective cyclopropanation of enals by oxidative N-heterocyclic carbene catalysis
作者:Anup Biswas、Suman De Sarkar、Ludger Tebben、Armido Studer
DOI:10.1039/c2cc31501g
日期:——
Carbene catalysed redox activation of alpha,beta-unsaturated aldehydes is applied for generation of alpha,beta-unsaturated acyl azoliums which undergo cyclopropanation upon reaction with a sulfur ylide and an alcohol to give the corresponding cyclopropanecarboxylic acid esters. With chiral carbenes good to excellent diastereo and enantioselectivities are obtained.
labeling methods for proteins are highly researched. Herein, we introduced β-carbonyl sulfonium compounds for selective cysteine modification in proteins within biological systems. Structural tuning led to sulfonium-based probes with high reactivity and selectivity. These probes show excellent biocompatibility, cell uptake, and specificity towards cysteine profiling in live cells.