三乙基铝或三乙基硼引发的烷基碘化物与α,β-不饱和化合物的自由基反应。

Triethylaluminum- or triethylborane-induced free radical reaction of alkyl iodides and alpha,beta-unsaturated compounds.

作者信息

Liu Jing-Yuan, Jang Yoeng-Jiunn, Lin Wen-Wei, Liu Ju-Tsung, Yao Ching-Fa

机构信息

Department of Chemistry, National Taiwan Normal University, 88, Section 4, Tingchow Road, Taipei, Taiwan 116, ROC.

出版信息

J Org Chem. 2003 May 16;68(10):4030-8. doi: 10.1021/jo020681b.

DOI:10.1021/jo020681b

PMID:12737587

Abstract

A series of alpha,beta-unsaturated compounds, 1a-c, 9, 13, and 17, were used as reactants in free radical conjugate addition reactions with different radicals generated from alkyl iodides such as 3, 4, or 5 in the presence of triethylborane-oxygen in air or via the use of triethylaluminum-benzoyl peroxide as a free radical initiator. When the reactions were carried out using triethylborane-air, the products, in most cases, were clean and were easily purified. However, higher yields of the 1,4-adducts and less side reactions occurred when less reactive substrates were used as Michael acceptors in reactions with triethylaluminum-benzoyl peroxide and alkyl iodide under similar conditions. A mechanism for this is proposed in Scheme 1.

摘要

一系列α,β-不饱和化合物1a - c、9、13和17，在空气存在下，以三乙基硼烷 - 氧气作为自由基引发剂，或通过使用三乙基铝 - 过氧化苯甲酰作为自由基引发剂，与由烷基碘（如3、4或5）产生的不同自由基进行自由基共轭加成反应。当使用三乙基硼烷 - 空气进行反应时，在大多数情况下，产物纯净且易于纯化。然而，在类似条件下，当使用反应活性较低的底物作为迈克尔受体与三乙基铝 - 过氧化苯甲酰和烷基碘进行反应时，1,4 - 加成产物的产率更高且副反应更少。方案1中提出了对此的一种机理。