Chemoselective protection of thiols versus alcohols and phenols. The Tosvinyl group
作者:Odón Arjona、Rocı́o Medel、Jenny Rojas、Anna M. Costa、Jaume Vilarrasa
DOI:10.1016/s0040-4039(03)01614-9
日期:2003.8
conjugate addition of aliphatic and aromatic thiols to ethynylp-tolylsulphone (tosylacetylene) has been managed to afford Tosvinyl derivatives chemoselectively (in the presence of oxygen nucleophiles) and stereoselectively (isomers Z) in practically quantitative yields. The conditions of choice are: catalytic amounts of Et3N (only 0.5–1.0 mol%), a reaction temperature around 0°C and, for the less acidic