RCH=CH2与过氧甲酸反应的量子化学研究

本文用MINDO/3方法研究了烯烃RCH=CH2(R=H, CH3, CHO和NO2)与过氧甲酸反应的机理。研究结果表明, RCH=CH2与过氧甲酸反应是亲电反应, 在加热条件下较容易进行。乙烯与过氧甲酸反应的过渡态具有局部对称结构; 若R为取代基时, 这种对称性不复存在, 对于R为给电子基, 过氧基的氧偏向与取代基相连的乙烯碳原子, R为吸电子基, 过氧基氧偏向乙烯的另一碳原子; 取代基的给、吸电子能力越强, 过渡态偏离对称结构越显著, 活化势垒降低或升高也越大。

A quantum chemical study of RCH=CH2 epoxidation by peroxyacid

MINDO/3 MO method has been used to study the reactions of peroxyformic acid with ethylene and substituted ethylenes. The results show that the reactions of RCH=CH2 (R = H, Me, CHO, NO2) with peroxyformic acid are electrophilic reactions. The activation energy decreases with R being electron donating substituent, while it increases by electron withdrawing substituents. Besides, when R = H, the transition structure (TS1) possesses local symmetry, as for R = Me, CHO, NO2, this symmetry no longer exists.