Domino reactions initiated by intramolecular hydride transfers from tri(di)arylmethane fragments to ketenimine and carbodiimide functions
作者:Mateo Alajarin、Baltasar Bonillo、Maria-Mar Ortin、Pilar Sanchez-Andrada、Angel Vidal、Raul-Angel Orenes
DOI:10.1039/c0ob00193g
日期:——
initial hydride shift, the tandem sequence continues with an alternative electrocyclization mode to give 9,10-dihydroacridines, (b) the full sequence is initiated by a rare 1,5 migration of an electron-rich aryl group, followed by a 6π-ERC which leads to 2-aryl-3,4-dihydroquinolines, or (c) a different [1,5]-H shift/6π-ERC sequence involving the initial migration of a hydrogen atom from a methyl group at
三芳基甲烷和二芳基甲烷片段作为氢化物供体参与热[1,5] -H转变/6π-ERC串联过程的能力 酮亚胺并且公开了碳二亚胺的功能。Ç -烷基- c ^ -苯基乙烯酮亚胺Ñ取代由三芳基甲烷亚结构转换成各种3,3,4,4-四取代-3,4-二氢喹啉,如结构上相关的碳二亚胺转化成3,4,4- trisubstituted- 3,4-二氢喹唑啉经瞬态邻-氮杂亚烷基。这些单锅法转换的第一步,即[1,5] -H位移,是基于三(二)芳基甲烷片段的已知亲水性和中心杂多聚碳原子的亲电性而认为是氢化物迁移原子,而最终的电环化涉及形成空间拥挤的C–C或C–N键。在C的情况下,C-二苯基取代的三芳基甲烷-烯酮亚胺由于在氮杂三烯体系的每个末端存在两个苯环而被禁止使用通常的6π-ERC。这种情况打开了新的反应通道:(a)在最初的氢化物转移之后,串联序列继续以另一种电环化模式产生9,10-二氢ac啶,(b)整个序列是由稀有的1