Ab initio studies on reaction H_2C═C(OH)Li+CH_3^+(CH_3^-)  

作　　者：王义贵 孙昌俊 邓从豪 

出　　处：《Science China Chemistry》1998年第6期587-595,共9页中国科学（化学英文版）

基　　金：ProjectsupportedbytheNationalNaturalScienceFoundationofChina (GrantNo .2 97730 2 5 )

摘　　要：The possible structures and isomerizations of H 2C C（OH）Li are studied theoretically by the gradient analytical method at RHF/631+G* level. According to these results, reactions of H 2C C（OH）Li with CH 3 + and CH 3 - are investigated thoroughly. When H 2C C（OH）Li reacts with CH 3 +, H 2C C（OH）Li firstly changes from structure 1 to structure 4, and then combines with CH 3 +. In this reaction, the configuration of central carbon is retained. When H 2C C（OH）Li reacts with CH 3 -, structure 1 firstly breaks its CO bond to give contact ionpair. Then through transition state 16 which is similar to structure 2, the attack of CH 3 - from the opposite side of -OH replaces -OH group and inverts the configuration of carbenoid carbon atom. All the results show that the ambident reactivity of carbenoid has close relationship with the stability of special structures.The possible structures and isomerizations of H 2C C(OH)Li are studied theoretically by the gradient analytical method at RHF/6_31+G* level. According to these results, reactions of H 2C C(OH)Li with CH 3 + and CH 3 - are investigated thoroughly. When H 2C C(OH)Li reacts with CH 3 +, H 2C C(OH)Li firstly changes from structure 1 to structure 4, and then combines with CH 3 +. In this reaction, the configuration of central carbon is retained. When H 2C C(OH)Li reacts with CH 3 -, structure 1 firstly breaks its C_O bond to give contact ion_pair. Then through transition state 16 which is similar to structure 2, the attack of CH 3 - from the opposite side of -OH replaces -OH group and inverts the configuration of carbenoid carbon atom. All the results show that the ambident reactivity of carbenoid has close relationship with the stability of special structures.

关 键 词：CARBENOID structure ISOMERIZATION ambident REACTIVITY ACYL ANION equivalent. 

分 类 号：O643.1[理学—物理化学]