The Synthesis of Internal Conjugated (<i>E</i>)-Enynyldialkylboranes and Their Applications to the Syntheses of Conjugated Alkynones, Conjugated (<i>E</i>)-Enynes, and Conjugated Enynes Bearing an Unsaturated Group on the Double Bond
作者:Masayuki Hoshi、Yuzuru Masuda、Akira Arase
DOI:10.1246/bcsj.58.1683
日期:1985.6
(E)-Enynyldialkylboranes, thus obtained, gave regio- and/or stereospecifically defined corresponding conjugated alkynones by alkaline hydrogen peroxide oxidation, conjugated (E)-enynes by protonolysis with acetic acid, and conjugated enynes bearing an unsaturated group on the internal alkenyl carbon atom by bis(acetylacetonato)copper-catalyzed cross-coupling reaction with allyl bromide or 1-bromo-1-hexyne respectively
In the presence of phosphine catalyst and pinacolborane, ynones undergo 1,2-reduction while ynoates undergotrans-hydroboration. Mechanistic insights into the two competing pathways lay grounds for control of selectivity in these processes.