have HOMO’s of low energy levels prefer benzylic carbon to attack. The nucleophilic substitution on the sulfur or the cyanide carbon generates CN− or p-xylene-α-thiolate anion, strong nucleophiles, as the primary products, which then initiate the complex secondary reactions. The selective reactivities of three attackingsites for nucleophiles in 1 have been rationalized in terms of MO theory.
已经研究了 4-甲基苄基硫氰酸酯 (1) 与几种亲核试剂的反应。化合物1具有三个亲电位点,即苄基碳、硫和氰基碳,以接受亲核攻击。具有高能级 HOMO 的 PhS− 和 CN− 似乎优先攻击硫原子。发现 MeO- 优先攻击氰化物碳,而具有低能级 HOMO 的胺优先攻击苄基碳。硫或氰化物碳上的亲核取代生成 CN- 或对二甲苯-α-硫醇盐阴离子,强亲核试剂,作为初级产物,然后引发复杂的次级反应。根据 MO 理论,1 中亲核试剂的三个攻击位点的选择性反应性已被合理化。
TANIMOTO, SHIGEO;NOZAWA, SHIGEO;INOUE, YOSHIHIKO, BULL. INST. CHEM. RES. KYOTO UNIV., 68,(1990) N, C. 193-198