Influences of alpha-substituent in 4,5-dimethoxy-2-nitrobenzyl-protected esters on both photocleavage rate and subsequent photoreaction of the generated 2-nitrosophenyl ketones: A novel photorearrangement of 2-nitrosophenyl ketones
作者:Noriko Chikaraishi Kasuga、Yusuke Saito、Naomichi Okamura、Tatsuya Miyazaki、Hikaru Satou、Kazuhiro Watanabe、Takaaki Ohta、Shu-hei Morimoto、Kazuo Yamaguchi
DOI:10.1016/j.jphotochem.2016.01.012
日期:2016.5
afford a bicyclic oxazole via a shift of the isopropyl group to the bridgehead position, resulting in loss of aromaticity of the six-membered ring. 2-Nitrosopheyl ketone bearing a tertiary-butyl substituent gives mainly azoxy and azo compounds via intermolecular reaction of nitrosoketones with loss of isobutene. The photorearrangement does not proceed in the case of the phenyl-substituted compound. These
当2-硝基苄基中的α-位置被支链烷基取代时,紫外线(UV)诱导的2-硝基苄基酯的光脱保护以释放酸并形成相应的2-硝基酮。所产生的2-亚硝基苯基酮取决于α-取代基的性质而经历多种光反应,包括独特的光重排。带有异丙基取代基的2-硝基酮主要经过这种重排,从而通过异丙基移至桥头位置而得到双环恶唑,从而导致六元环的芳香性损失。带有叔丁基取代基的2-亚硝基苯甲酮主要通过亚硝基酮的分子间反应与异丁烯的损失而产生氮杂和偶氮化合物。在苯基取代的化合物的情况下,不进行光重排。这些发现将有助于选择和/或设计对光不稳定的保护基。