Either of electroreduction or Mg-promoted electron-transfer reaction of vinylphosphonate derivatives 1-4 in the presence of acid anhydrides 5 a - c or acid chlorides 15 b, c brought about regioselective C-acylation to give the corresponding β-acylphosphonates 3 in good yields. The reaction may be initiated through one-electron transfer from either a cathode or Mg metal to a substrate to give the corresponding anion radical, which is then subjected to electrophilic attack of an acylating agent, followed by the fast second electron-transfer.
在酸酐5a-c或酰
氯15b、c的存在下,
乙烯膦酸酯衍
生物1-4无论是通过电还原还是Mg促进的电子转移反应,均能选择性地发生C-酰化反应,得到相应的β-酰基
膦酸酯3,产率良好。反应可能始于从一个阴极或Mg
金属向底物的一次电子转移,生成相应的阴离子自由基,随后遭受酰化剂的亲电攻击,继而迅速进行第二次电子转移。