The cyclization of N-allyl-N-carbetoxy-substituted aminothiophenes and furans was performed by intramolecular Pd(II)-catalyzed oxidative coupling. The process involves a nucleophilic attack of a heteroaromatic carbon to the internal carbon of the Ï-olefin complex through a 5-exo-trig ring-formation. Better conditions required PdCl2(MeCN)2 as catalyst, CuCl2 as co-catalyst and an environmentally friendly reoxidant such as O2 to promote the catalytic cycle.
通过分子内
钯(II)催化的氧化偶联,实现了 N-烯丙基-N-羧基取代的
氨基
噻吩和
呋喃的环化。该过程涉及杂芳香族碳通过 5- 外三向环化作用对Ï-烯烃复合物内部碳的亲核攻击。较好的条件需要 PdCl2(MeCN)2 作为催化剂,CuCl2 作为助催化剂,以及 O2 等环境友好型还原剂来促进催化循环。