acid or a boronic acid. This provides an interesting alternative to an aldol reaction when combined with the straightforward addition of an alkyne to an aldehyde or ketone. The gold-catalysed reaction of an electron-deficient, sterically hindered propargylic alcohol with a boronic acid led to the formation of an unusually stable cyclic boron enolate.
可以通过添加具有7-9的pKa的质子性添加剂(例如
对硝基苯酚,
硼酸或
硼酸。当将
炔烃直接添加到醛或酮中时,这为醛醇缩合反应提供了有趣的替代方法。电子缺陷的,位阻的炔丙基醇与
硼酸的
金催化反应导致形成异常稳定的环状烯醇
硼。