氧化腈与丙炔1,3-偶极环加成反应中区域选择性的理论研究

用密度泛函(DFT)B3LYP/6-311＋＋G**方法研究了氧化腈(RCNO, R＝F, NO₂, OCH₃, OH, COOCH₃, CHO, CONH₂, H, CH₃)与丙炔的1,3-偶极环加成反应, 并且计算了不同温度下的反应速率常数, 讨论了氧化腈上不同取代基R的取代效应和温度对反应区域选择性的影响. 结果显示, 氧化腈与富电子亲偶极体——炔烃反应, 5-取代反应占优势; 氧化腈上取代基R为强吸电子基团时或在较高温度下, 有利于4-取代反应的进行.

Theoretical Study on the Regioselectivity of Nitrile Oxide 1,3-Dipolar Cycloaddition to Propyne

In order to discuss the regioselectivity of nitrile oxide 1,3-dipolar cycloaddition to propyne, 1,3-dipolar cycloaddition reaction of substituted nitrile oxide (RCNO, R＝F, NO₂, OCH₃, OH, COOCH₃, CHO, CONH₂, H, CH₃) with propyne was studied using density functional theory at the 6-311＋＋G** level, and the reaction rates were calculated at different temperature from 200 to 400 K. The conclusions are that 5-substituted reaction of nitrile oxide with electron-deficient dipolarophile—propyne is dominant, while 4-substituted reaction of electron-deficient nitrile oxide with propyne is favored at relatively high temperature.