作者:Shyam S. Samanta、Stéphane P. Roche
DOI:10.1002/ejoc.201901033
日期:2019.10.24
A general and efficient synthesis of α-haloglycine esters from commercially available feedstock chemicals, in a single step, is reported. The reactivity of these α-haloglycine esters with various nucleophiles was studied as surrogates of α-iminoesters upon activation with hydrogen-bond donor catalysts. DFT calculations on the α-haloglycine structures (X = F, Cl, Br) accompanied by an X-ray characterization
报道了一种从市售原料化学品中一步通用和有效合成 α-卤代甘氨酸酯的方法。这些 α-卤代甘氨酸酯与各种亲核试剂的反应性被研究为 α-亚氨基酯在用氢键供体催化剂活化后的替代物。α-卤代甘氨酸结构 (X = F, Cl, Br) 的 DFT 计算伴随着 α-溴甘氨酸酯的 X 射线表征支持由超共轭产生的“广义”异头效应的存在。这种特殊的超共轭效应被认为是导致卤素核疏散性增强的原因,导致氢键供体催化剂容易提取卤素。