Vinylphosphonium Salts and Allenes from Carbonyl Compounds Using Titanium-Substituted Ylides
作者:Kelly A. Reynolds、Pablo G. Dopico、Marcus S. Brody、M. G. Finn
DOI:10.1021/jo961000d
日期:1997.4.1
allene synthesis. This methodology, along with a previously reported one-pot reaction, comprises the most convenient route available for the synthesis of 1,3-disubstituted allenes. The metal-substituted ylide reagent may be generated in situ from commercially-available starting materials. Two representative vinylphosphonium salts were shown to undergo reversible isomerization to the (Z)-form upon irradiation
(E)-乙烯基phosph盐可从羰基化合物与钛取代的内酯物种(Me(2)N)(3)P = CHTi(OiPr)Cl(2)或(Me(2)N)( 3)P = CHTi(OiPr)(2)Cl。虽然可以容忍各种各样的不可烯化的醛,但叶立德碳周围的空间体积将过程限制为高度活化或不受阻碍的酮。乙烯基phosph盐可通过去质子化并与第二种醛缩合而转化为丙二烯,从而完成两步双烯烃化丙二烯的合成。该方法学以及先前报道的一锅法反应,包括可用于合成1,3-二取代的烯丙基的最方便的途径。金属取代的内酰胺试剂可以由商业上可获得的原料原位产生。