Conjugate Addition versus Cycloaddition/Condensation of Nitro Compounds in Water: Selectivity, Acid-Base Catalysis, and Induction Period
作者:Luca Guideri、Francesco De Sarlo、Fabrizio Machetti
DOI:10.1002/chem.201202698
日期:2013.1.7
react in water as in chloroform with electron‐deficient dipolarophiles to give condensation or conjugate addition products under base catalysis. In general, high selectivity towards condensation is observed in water, with shorter induction periods than in chloroform. In water, condensations slowly occur even without base; kinetic profiles evidence the catalytic effect of the base, which should be related
硝基乙酸盐和硝基乙酰胺在水中(如氯仿中)与缺电子的双极性亲和剂反应,在碱催化下生成缩合或共轭加成产物。通常,在水中观察到对缩合的高选择性,诱导时间比在氯仿中短。在水中,即使没有碱,凝结也会缓慢发生。动力学曲线证明了碱的催化作用,这与转化为互变异构体硝酸有关。水中的冷凝可方便地获得带有各种官能团(包括铵,羧基和羧酰胺)的异恶唑衍生物。