Reaction of 1,3-dioxolans with iodine monochloride: the scope and mechanism of formation of 1,3-dioxolan-2-ylium dichloroiodates(I)
作者:Andr� Goosen、Cedric W. McCleland
DOI:10.1039/p19810000977
日期:——
salts, crystalline products could not be isolated from 4,5-disubstituted dioxolans. The reaction was inhibited by electron-withdrawing 4- and 5-substituents. From a study of the effects of photolysis and added iodine, the mechanism is proposed to involve a hydride ion transfer. Possible reasons for the formation of dichloroiodate(I) rather than monohalide salts, are outlined. The stability of the 2-aryl-substituted
用一氯化碘处理一系列的2-取代的4,4,5,5-四甲基-1,3-二氧戊环,得到合适的2-取代的4,4,5,5-四甲基-1,3-二氧戊环-二氯碘酸2-基鎓盐(I)具有极好的收率。与稳定的2-芳基取代的盐相反,2-烷基和未取代的衍生物相对不稳定。虽然2-苯基-1,3-二氧戊环和2-苯基-1,3-二氧六环的不稳定盐收率低,但无法从4,5-二取代的二氧戊环中分离出结晶产物。该反应被吸电子的4-和5-取代基抑制。通过对光解作用和添加碘的影响的研究,提出了涉及氢化物离子转移的机理。形成二氯碘酸盐的可能原因(I概述了)而不是一卤化物盐。根据阳离子中的电荷分布和可能的芳基-阴离子相互作用,讨论了2-芳基取代盐的稳定性。