The Stille Reaction of 1,1-Dibromo-1-alkenes: Preparation of Trisubstituted Alkenes and Internal Alkynes
作者:Wang Shen、Le Wang
DOI:10.1021/jo991116k
日期:1999.11.1
The Stille reaction of 1,1-dibromo-1-alkenes 1 with aryl- and vinylstannanes produces different products depending on the reaction conditions. When the reaction is run in toluene or 1,4-dioxane with tris(2-furyl)phosphine (TFP) as the ligand, (Z)-bromoalkenes 2 are obtained stereospecifically in good to excellent yields with most substrates. However, 2-aryl-1,1-dibromo-1-alkenes (1e,1g) having an electron-donating
1,1-二溴-1-烯烃1与芳基和乙烯基锡烷的斯蒂勒反应根据反应条件产生不同的产物。当反应在甲苯或1,4-二恶烷中以三(2-呋喃基)膦(TFP)为配体进行时,对于大多数底物,立体定向获得(Z)-溴代烯烃2的产率高至优异。然而,在对位或邻位具有供电子甲氧基的2-芳基-1,1-二溴-1-烯(1e,1g)收率很低。该方法已应用于立体有择的三取代烯烃5的一锅合成。当在高偶极溶剂(DMF)中进行Stille反应时,一溴化物2和/或内部炔烃4就是产物。不管使用哪种配体,反应性较低的苯基锡烷都有利于炔烃4的形成。反应性更高的有机锡烷(乙烯基,