1,3-Dipolar cycloaddition of nitrile imines with α,β-unsaturated lactones, thiolactones and lactams: synthesis of ring-fused pyrazoles
作者:Jay Zumbar Chandanshive、Pedro Blas González、William Tiznado、Bianca Flavia Bonini、Julio Caballero、Cristina Femoni、Mauro Comes Franchini
DOI:10.1016/j.tet.2012.02.068
日期:2012.4
1,3-Dipolar cycloaddition of nitrile imines with α,β-unsaturated five- and six-membered lactones, thiolactones and lactams gave ring-fused pyrazoles. Regioisomeric mixtures have been obtained with the 5-substituted pyrazole as the major cycloadduct. Only with the five-membered lactone the major product was the 4-acyl derivative. Computational studies, the use of the topological analysis of the Fukui
腈亚胺与α,β-不饱和五元和六元内酯,硫代内酯和内酰胺的1,3-偶极环加成反应得到环稠合的吡唑。已经获得了以5-取代的吡唑为主要环加合物的区域异构体混合物。只有五元内酯的主要产物是4-酰基衍生物。计算研究,对Fukui函数的拓扑分析和势能面(PES)理论的使用允许对局部反应性进行理论描述,与观察到的高区域化学性质以及与羰基相邻的杂原子的作用相吻合。