作者:Tetsuji Itoh、Yoshinobu Jinbo、Katsuyuki Hirai、Hideo Tomioka
DOI:10.1021/jo049718d
日期:2004.6.1
by photolysis of those ethynylated diphenyldiazomethanes were characterized by ESR and UV−vis spectroscopies at low temperature and laser flash photolysis techniques in solution at room temperature. Although ESR data indicated that ethynyl groups at the ortho positions are likely to stabilize triplet DPCs both sterically and electronically more effectively than o-bromine groups, kinetic studies suggested
(2,4,6-三溴苯基)(4-叔丁基-2,6-二甲基苯基)重氮甲烷(1a)表现出足够的稳定性,足以在高温下经受Sonogashira偶联反应条件的影响,不仅产生了对-单取代产物,(4-三甲基甲硅烷基乙炔基-2,6-二溴苯基)(4-叔丁基-2,6-二甲基苯基)重氮甲烷(1b),也是一种双取代的[2,4-双(三甲基甲硅烷基乙炔基)-6-溴苯基](4-叔丁基-2,6-二甲基苯基)重氮甲烷(1c)和三取代产物[2,4,6-三(三甲基甲硅烷基乙炔基)苯基](4-叔丁基-2,6-二甲基苯基)重氮甲烷(1d)。通过乙炔化二苯基重氮甲烷的光解生成的三重态二苯卡宾(DPC)的特征在于,在低温下采用ESR和UV-vis光谱学,在室温下采用溶液中的激光闪光光解技术。尽管ESR数据表明,乙炔基在邻位可能会趋于稳定三重DPC的两个空间和电子更有效地比Ø -溴集团,动力学研究表明,三联毛乳头细胞的稳定性没有增加Ø乙炔