作者:Stephen A. Glover、Andre Goosen、Cedric V. McClei、Johan L. Schoonraad
DOI:10.1016/s0040-4020(01)81665-3
日期:——
solvents. These intermediates readily cyclise onto aromatic nuclei on alkozy side-chains to give benzoxazines and benzoxazepines and on the acyl side-chains to give γ, δ and ϵ benzolactams. Spirane products are formed by ipso addition When a 4-methoxy substituent ia present on the side-chain aromatic rings. The yields and regioselectivities of these reactions have been ascribed to different transition structures
N-烷氧基-N-酰基硝鎓离子是通过在醚溶剂中用银离子处理N-烷氧基-N-氯酰胺类生成的。这些中间体很容易环化到醇酸侧链上的芳香核上,得到苯并恶嗪和苯并x氮平,以及酰基侧链上的γ,δ和ϵ苯并内酰胺。当在侧链芳环上存在4-甲氧基取代基时,通过ipso加成形成尖晶石产物。这些反应的产率和区域选择性归因于不同的过渡结构,用于环化到分别涉及胞外和环内N-0π键的酰基和烷氧基侧链上。从MNDO计算中获得了这种极高的π键特性的证据,该计算预测π键阶为0.9,旋转势垒为29.7 kcalmol -1