【摘要】 以脯氨酸为起始原料合成了四个光反应底物N-(末端三甲基硅苄基脯氨酸肽链)邻苯二甲酰亚胺(4),并在甲醇溶剂中进行了光反应.结果表明,4的光致激发态分子内发生单电子转移反应,生成双离子自由基8,电子沿着化学键在给电子杂原子间转移,达到共振平衡,离去基团离去使平衡向末端杂原子方向移动,高选择性地生成分子内端位双自由基9,自由基偶合生成标题化合物5.此反应产率较好,区域选择性高,所有新化合物结构均经NMR和质谱验证.更多还原

【Abstract】 Four photoreactants N-(amidosilane terminated polyproline peptide chain)phthalimide(4a～4d) were synthesized by using proline as the starting material,and were irradiated in methanol.The results confirmed that photoinduced excited states of 4a～4d were observed to promote formation of zwitterion biradical (8)by single electron transfer in the molecule.In this process,intrachain SET(ISET)happened among electron donors and an equation of resonant appeared.Intermolecular biradicals(9)were formed in high selectivity by shuck off the leaving group of 1,ω-zwitterionic biradicals(8).The biradicals 9 copulated to give the title compound cyclopeptides 5 in high yield and high regioselectivity.Structures of all compounds were characterized by FAB-MS,NMR techniques.更多还原