诱导效应 X> OCOR> OR >-NH 2 共轭效应 X OCOR< OR <-NH 离去能力 Ⅹ>OCOR>OR>-NH2Organic Chemistry Organic Chemistry Xiamen Xiamen University University X > OCOR > OR > NH 2 X < OCOR < OR < NH 2 诱导效应 共轭效应 X > OCOR > OR > NH 2 离去能力