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.
基金
ProjectsupportedbytheNationalNaturalScienceFoundationofChina (GrantNo .2 97730 2 5 )
