دانلود گزارش کارورزی و کار آموزی

چکیده : 

Thiocarbonyl ene reactions via CAS and CAC bond formation routes have been performed using DFT

method at B3LYP/6-31G**//B3LYP/6-31G* level, indicating that both routes undergo concerted mechanism.

The reactions with 10 substituents on enophile were further examined. It was found that substituent

affects the activation energy and regioselectivity. An electron withdrawing group lowers the

activation energy and prefers the CAS bond formation pathway, while the reaction with an electron

donating group prefers the CAC bond formation route with higher barrier. It is worth noting that a very

strong electron donating group is kinetically and thermodynamically unfavorable for the thiocarbonyl

ene reaction. The substitution effect was explained by the reactivity index and charge transfer. And

the charge difference on C1 and S in enophile controls the regioselectivity.