Detection and Reaction of Oxaphosphetanes Derived from Benzaldehyde and 1-Adamantylmethylidene Ylide
作者:Hiroshi Yamataka、Tsutomu Takatsuka、Terukiyo Hanafusa
DOI:10.1021/jo951025x
日期:1996.1.1
Wittig reaction of (1-adamantylmethylidene)triphenylphosphorane (Ph(3)P=CH(1-Ad)) with benzaldehyde was investigated, and the results were compared with those of other ylides. The substituent effect in the reaction of the ylide with benzaldehydes was determined by competition experiments, which gave a Hammett rho value of 3.2. The rho value is much larger than those reported for analogous reactions of
研究了(1-金刚烷基亚甲基)三苯基磷烷(Ph(3)P = CH(1-Ad))与苯甲醛的Wittig反应,并将其与其他烷基化物的结果进行了比较。通过竞争实验确定了叶立德与苯甲醛反应中的取代基效应,其Hammett rho值为3.2。rho值远大于Ph(3)P = CH(CH(CH(2))(2)CH(3)(rho = 0.20)和Ph(3)P = CH(CH(3) ))(2)(rho = 0.59),表明对于Ph(3)P = CH(1-Ad)和其他烷基化物,反应机理不同。与母体苯甲醛反应时,产物烯烃的顺/反比为74/26,高度取决于取代基的位置。邻位取代的苯甲醛可得到高达90%的反式烯烃。通过(31)P NMR监测反应发现,同时形成了顺式和反式氧杂膦烷中间体,并且顺式氧杂磷杂环丁烷的形成和分解比反式氧杂磷环丙烷快7-12倍。通过比较Ph(3)P = CH(1-Ad)+苯甲醛与Ph(3)P =