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 ethynyl p-tolyl sulphone (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
已经设法将脂族和芳族硫醇共轭加成到乙炔基对甲苯基砜(甲苯磺酰基乙炔)中,以实际上定量的产率化学地(在氧亲核试剂存在下)和立体选择性地(异构体Z)提供Tosvinyl衍生物。选择的条件是:催化量的Et 3 N(仅0.5-1.0 mol%),反应温度约为0°C,对于酸性较低的硫醇,则为CF 3 CH 2 OH或CH 3 CN / CF 3 CH 2 OH为溶剂。因此,Ñ -Boc-CYS-OME已定量地保护作为其小号在存在-Tosvinyl衍生物Ñ-Boc-Ser-OMe和N -Boc-Tyr-OMe。这种新颖的保护基团对几种碱性和酸性条件均稳定。通过在室温下用过量的吡咯烷处理或在0℃下用链烷硫醇根离子处理可将其去除。