Nucleohomolytic substitution at boron: A computational approach

被引:19
作者
Carra, Claudio [1 ]
Scaiano, Juan C. [1 ]
机构
[1] Univ Ottawa, Dept Chem, Ottawa, ON K1N 6N5, Canada
基金
加拿大自然科学与工程研究理事会;
关键词
boron; nucleophilic substitution; density functional calculations; radicals;
D O I
10.1002/ejoc.200800187
中图分类号
O62 [有机化学];
学科分类号
070303 ; 081704 ;
摘要
A theoretical investigation is reported on the reaction mechanism for oxygen-centered radical attack on alkyl- and aryl-borane substrates, The model reveals how the mechanism, traditionally considered as a S(H)2 reaction, involves instead nucleophilic attack of the oxygen lone pair on the empty boron p orbital. The single electron on the oxygen is not directly involved in the process, however, as a result of a stereoelectronic effect: the bond aligned with the SOMO orbital is deactivated and the corresponding ligand leaves promptly as a radical species. The overall mechanism can be described as a nucleohomolytic reaction that shares many characteristics with conventional nucleophilic substitution. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008.
引用
收藏
页码:4454 / 4459
页数:6
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