Nucleophilic vinylic substitutions on unactivated substrates.
作者:L. Testaferri、M. Tiecco、M. Tingoli、D. Chianelli
DOI:10.1016/s0040-4020(01)96542-1
日期:1985.1
styryl alkyl sulphides and selenides, in DMF at 100°C, to give the products of vinylic or aliphatic substitution. The two nucleophilic reagents are extremely selective. In the case of RSNa the attack at the vinylic carbon atom is much faster than that at the aliphatic carbon atom and the (Z)- or (E)- styryl alkyl sulphides are obtained as the result of a stereospecific vinylic substitution which occurs
链烷硫醇钠或甲基硒化锂与苯乙烯基烷基硫化物和硒化物在100°C的DMF中反应,得到乙烯基或脂肪族取代的产物。两种亲核试剂具有极高的选择性。在RSNa的情况下,对乙烯基碳原子的攻击比对脂肪族碳原子的攻击快得多,并且由于立体特异性的乙烯基取代而保留而获得了(Z)-或(E)-苯乙烯基烷基硫化物。配置。相反,在MeSeLi的情况下,在相同的实验条件下,发生的唯一反应是脂肪族取代,该脂肪族提供硫醇乙烯基阴离子,为(E)-和(Z)-异构体的平衡混合物,或保留起始苯乙烯基烷基硒化物构型的乙烯基硒化物阴离子。