2-芳基戊二酸酯的合成

Synthesis of 2-Arylglutarate

在K2CO3-TEBA相转移催化体系中,4位或2位含有—NO2的苯磺酰基乙酸酯与α,β-不饱和酯发生加成-重排反应,制得2-芳基戊二酸酯,其收率较高(73%～87%)。研究了反应物-芳磺酰基乙酸酯苯环上取代基对加成-重排反应的影响,发现只有当芳环上4位或2位有硝基时,在K2CO3-TEBA相转移催化体系中,芳磺酰基乙酸酯与α,β-不饱和酯反应才可发生加成-重排反应,生成2-芳基戊二酸酯,其机理可能是芳磺酰基乙酸酯与α,β-不饱和酯首先发生Michael加成反应,随后加成产物发生分子内的亲核取代,酸化后脱去SO2得2-芳基戊二酸酯。而当芳环上4位或2位含有给电子基团(如,甲基)或弱吸电子基团(如,氯)时,却只能发生正常的Michael加成反应,生成相应的2-芳磺酰基戊二酸酯。

2-Arylglutarates with high yields （73% -87% ） were prepared by addition-rearrangement reactions of phenylsulfonylacetates containing 4-nitro or 2-nitro with α,β-unsaturated esters under K2CO3-TEBA phase transfer catalyst conditions. The effects of substistution groups at the phenyl ring of reactant-arylsulfonylacetates on the addition-rearrangement reaction were examined. Arylsulfonylacetate containing 4-nitro or 2-nitro at the phenyl ring was found to carry out the addition-rearrangement reaction to form 2-arylglutarates under K2CO3-TEBA phase transfer catalyst conditions. The meehanism is proposed that the Michael adduct reactions of arylsulfonylacetates with α,β-unsaturated esters resulted in the Michael adducts, which might rearrange to the inter mediate through intramolecular nucleophilic substitution, which might further lose sulfur dioxide and then led to 2-arylglutarates. The Michael adduct reactions of arylsulfonylacetates containing electron-donating groups （ for example ： methyl） or weakly absorbing groups （ for example ： chloro） at 4-position or 2-position of the phenyl ring with ct d3-unsaturated esters normally resulted in 2-arylsulfonylacetates.