Metallated ketenimines: Quinazoline derivatives from base induced dimerization of N-phenyldiethylketenimine. an experimental and theoretical study
作者:Rolf Gertzmann、Roland Fröhlich、Mathias Grehl、Ernst-Ulrich Würthwein
DOI:10.1016/0040-4020(95)00514-9
日期:1995.8
reaction sequence metallation at an aromatic ortho position is deduced. The methylene protons are not affected in the deprotonation. Addition of a second ketenimine 1 leads after ring closure to the heterocyclic anion 9, which is trapped by the electrophiles, yielding the quinazoline derivatives 2–7. The reaction sequence is interpreted in terms of a kinetically accelerated metallation. Semiempirical
N-苯基-二乙基酮亚胺1的去质子化可通过过量的强有机碱(叔丁基甲基醚中的2,2,6,6-四甲基哌啶,正丁基锂和叔丁醇钾)实现。通过使用三甲基乙酰氯和二甲基二硫化物作为亲电子试剂的捕集反应来研究所得的有机金属悬浮液。从为反应顺序的第一步获得的捕获产物的结构推导在芳族邻位金属化。亚甲基质子在去质子化中不受影响。闭环后向杂环阴离子9中添加第二个酮亚胺1导线,被亲电子试剂俘获,生成喹唑啉衍生物2-7。反应序列根据动力学加速的金属化来解释。N-苯基-二乙基酮亚胺1气相酸性的半经验计算(MNDO,PM3)支持该分析。另外,讨论了中间体单体锂化合物10和11的优化结构的量子化学结果。