Single Electron Transfer in Nucleophilic Aliphatic Substitution. Evidence for Single Electron Transfer in the Reactions of 1-Halonorbornanes with Various Nucleophiles
摘要:
A series of 1-halonorbornanes was used as a model system in reactions with several nucleophiles in order to determine the involvement of single electron transfer (SET) in nucleophilic aliphatic substitution in the absence of light. The 1-halonorbornanes were allowed to react with Me3Sn-, Ph2P-, AlH4-, N(iPr)2-, SPh-, and the 2-nitropropyl anion in ether solvents at room temperature to 0-degrees-C. The results of product analyses, the use of radical and radical anion trapping reagents, the results of deuterium labeling studies, and the nucleofugality effect support a SET mechanism for the reactions involving 1-iodonorbornane. Convincing evidence that reduction of hindered alkyl iodides with LiAlH4 takes place by a SET pathway rather than by an impurity-initiated halogen atom radical chain process followed by an S(N)2 pathway, is presented.
Deoxygenation of aldehydes and ketones; a new general reaction of dibromocarbene and dibromocarbonyl ylides
作者:Zhenwei Huan、John A. Landgrebe、Kimberly Peterson
DOI:10.1016/s0040-4039(00)88035-1
日期:1983.1
The treatment of a variety of aldehydes and ketones with phenyl)tribromomethyl)mercury results in the production of carbon monoxide from the deoxygenation of the carbonyl group by dibromocarbene.
用苯基(三溴甲基)汞处理各种醛和酮会导致羰基被二溴卡宾脱氧而生成一氧化碳。
Radical brominations of alkanic positions by bromine and by N-bromosuccinimide
作者:James G. Traynham、Yu-Sun Lee
DOI:10.1021/ja00818a036
日期:1974.5
of rudical brominations of alkanes, and in particular the influence of a bromo substituent on the selectivity in the hydrogen-abstraction step, have been studied and debated by several groups of investigators. Central to the controversy is the mechanism of bromination by N-bromosuccinimide (NBS), for some of the proposals are supported almost solely by the pre sumed sameness of bromination mechanism