Chemoselectivity in reactions of an α-diazo-β-diketone with some conjugative double-bond systems
作者:Jiaxi Xu、Qihan Zhang、Liangbi Chen、Hui Chen
DOI:10.1039/b103173m
日期:——
Reactions of 2-diazo-1,3-diphenylpropane-1,3-dione with α,β-unsaturated aldehydes and ketones, and keto-imines, in refluxing anhydrous toluene indicate that benzoyl(phenyl)ketene, which is generated by the thermal Wolff rearrangement of 2-diazo-1,3-diphenylpropane-1,3-dione, shows a pronounced tendency to form chemospecific [2 + 4] DielsâAlder adducts with the carbonyl group in α,β-unsaturated aldehydes and ketones, and the imine group in keto-imines. The reactivity in reactions of the α-diazo-β-diketone with these conjugative double-bond systems is CN > CO > CC. However, benzoyl(phenyl)ketene reacts with α,β-unsaturated imines to produce chemospecific [2 + 2] cycloadducts: β-lactams.
2-二氮基-1,3-二苯基丙烯-1,3-二酮与α,β-不饱和醛和酮以及酮亚胺在回流无水甲苯中的反应表明,通过热的沃尔夫重排生成的苯甲酰(苯基)烯酮,显示出与α,β-不饱和醛和酮中的羰基及酮亚胺中的亚胺基形成化学特异性[2+4]戴尔斯-阿尔德加合物的显著倾向。α-二氮基-β-二酮与这些共轭双键体系的反应活性顺序为CN > CO > CC。然而,苯甲酰(苯基)烯酮与α,β-不饱和亚胺反应生成化学特异性[2+2]环加合物:β-内酰胺。