Synthesis of pyrazolo[5,1-a]isoquinolines via silver(i)–rhodium(i) cooperative catalysis in the reaction of N′-(2-alkynylbenzylidene)hydrazide with cycloprop-2-ene-1,1-dicarboxylate
作者:Liangqing Yao、Xingxin Yu、Chen Mo、Jie Wu
DOI:10.1039/c2ob26824h
日期:——
A tandem reaction between N′-(2-alkynylbenzylidene)hydrazide and cycloprop-2-ene-1,1-dicarboxylate co-catalyzed by silver triflate and tris(triphenylphosphine)rhodium chloride is reported. The reaction proceeds through 6-endo-cyclization, [3 + 2] cycloaddition, cyclopropane opening, and aromatization, leading to pyrazolo[5,1-a]isoquinolines in moderate to good yields.
N '-(2-炔基亚苄基)酰肼与环丙-2-烯-1,1-二羧酸酯共催化下的串联反应三氟甲磺酸银报道了三(三苯基膦)氯化铑。该反应通过6-内-cyclization,[3 + 2]环加成,环丙烷打开并进行芳构化,导致吡唑并[5,1- a ]异喹啉的产量适中至良好。