Rhodium-catalyzed arylthiolation reaction of nitroalkanes, diethyl malonate, and 1,2-diphenylethanone with diaryl disulfides: control of disfavored equilibrium reaction
作者:Mieko Arisawa、Yuri Nihei、Masahiko Yamaguchi
DOI:10.1016/j.tetlet.2012.07.132
日期:2012.10
diaryl disulfides were employed depending on the substrate: di(p-chlorophenyl) disulfide was used for the thiolation reaction of 1-nitroalkanes, 1-nitrocyclopentane and 1-nitrocycloheptane with acidic α-protons (pKa 16 and 17); di(p-methoxyphenyl) disulfide for 1-nitrocyclobutane and 1-nitrocyclohexane with less acidic α-protons (pKa ca. 18). Related reactivities were observed in the thiolation reactions
在催化量的RhH(PPh 3)4和1,2-双(二苯基膦基)乙烷(dppe)存在下,1-硝基烷烃与二芳基二硫化物反应,在空气中生成1-芳硫基-1-硝基烷烃。铑催化的巯基氧化为二硫化物和水的反应使形成热力学不利产物的平衡发生了变化。环状硝基烷烃的硫醇化反应可以高收率进行,只要根据基材使用合适的二芳基二硫化物即可:二(对氯苯基)二硫化物用于1-硝基烷烃,1-硝基环戊烷和1-硝基环庚烷与酸性α的硫醇化反应。 -质子(p K a 16和17); 二(p甲氧基苯基)二硫化物1-nitrocyclobutane和1-硝基环己烷较少酸性α质子(对ķ一个约18)。在丙二酸酯和1,2-二苯乙酮的硫醇化反应中观察到相关的反应性。