Titanium(IV) Enolates of 2-Nitrocarboxylic Esters and Their Oxidative Chlorination. A Convenient Route to α-Chloro-α-nitrocarboxylates
作者:Dariusz Cież、Justyna Kalinowska-Tłuścik
DOI:10.1055/s-0031-1290081
日期:2012.1
A new method for the synthesis of 2-chloro-2-nitrocarboxylic esters from 2-nitrocarboxylates is described. The procedure consists of the oxidative chlorination of titanium(IV) enolates of 2-nitro esters in the presence of ammonium nitrate. Esters of 2-chloro-2-nitrocarboxylic acids are formed in very good to quantitative yields. Application of this method for the chlorination of α,α′-dinitrodicarboxylates
描述了一种由2-硝基羧酸酯合成2-氯-2-硝基羧酸酯的新方法。该方法包括在硝酸铵存在下对2-硝基酯的钛(IV)烯醇钛进行氧化氯化。以非常好的定量产率形成了2-氯-2-硝基羧酸的酯。该方法在氯化α,α'-二硝基二羧酸酯中的应用导致α,α'-二氯-α,α'-二硝基羧酸酯具有高内消旋-非对映选择性。反应混合物中不存在硝酸铵影响硝基的还原并导致2-硝基羧酸酯部分转化为2-(羟基亚氨基)羧酸酯。 氧化氯化-烯醇钛-非对映选择性-酯-过渡态