proceeds by a concerted [2+1] cycloaddition with a very low energy barrier to afford a pentacoordinate oxasilirane (see scheme). This result clearly demonstrates the behaviour of phosphonium sila–ylides as nucleophilic silylenoids.
稳定核芯:与不稳定的瞬态亚甲
硅烷基(与羰基化合物反应形成供体-受体加合物)相反,膦配位的亚甲
硅烷基与醛的反应是通过协同的[2 + 1]环加成与具有非常低的能垒,可提供五配位的氧杂
硅氧烷(请参阅方案)。该结果清楚地证明了sil
硅烷基化物作为亲核
硅基类化合物的行为。