New methodology for the [4+3] cycloaddition reactions: generation of oxyallyl cations from α,α′-diiodoketones under sonochemical or thermal conditions
作者:Angel M Montaña、Pedro M Grima
DOI:10.1016/s0040-4039(01)01671-9
日期:2001.10
A new methodology to perform [4+3] cycloaddition reactions of suitable dienes and 1,3-dimethyl-2-oxyallyl cations is presented. The reaction is carried out starting from commercially available dienes and easy-handling α,α′-diiodoketones, which are reduced by the Zn/Cu couple to generate the oxyallyl cation as intermediate. The reaction is carried out under mild thermal or sonochemical conditions at
提出了一种进行合适的二烯与1,3-二甲基-2-氧基烯丙基阳离子的[4 + 3]环加成反应的新方法。该反应从可商购获得的二烯和易于处理的α,α′-二碘酮开始进行,所述α,α′-二碘酮通过Zn / Cu对被还原以产生作为中间体的羟基烯丙基阳离子。该反应在温和的热或声化学条件下于低温(0至-44°C)下进行,反应时间短(<15分钟)。该方法学代表了基于其他还原剂或从更复杂的羟烯丙基阳离子前体开始的实际程序的良好替代性方面。