regioselectivity. For both substrates a decrease in activity with an increase in bite angle is observed. It is suggested that the aforementioned rates of β-hydrogen elimination versus CO insertion must play a crucial role in this bite angle effect on activity, because previous studies have shown that an increase in bite angle leads to an increase in activity.
一种新颖的
配体系列的(1 - 10),该诱导宽咬角(106°<β Ñ <131°)已被合成。与黄磷系列(例如13对5)相比,磷环部分的引入导致配体具有稍大的咬合角。高压IR和RhH的(CO)的(二膦)的高压NMR研究2种复合物显示,大多数配体(3 - 7)采用双赤道结合模式只在三角双锥铑络合物。配体结构的细微变化对1-辛烯和反式的羰基化反应的活性和选择性有很大影响-2-辛烯。速率高达3275(摩尔醛)(摩尔铑)- 1 H ^ - 1(p(CO / H 2)= 20巴,Ť = 353 K,铑[Rh] = 1毫米,[1-辛烯] = 637毫摩尔)当以1-辛烯为底物时,对线性产物的区域选择性> 99%。对于反式-2-辛烯速率高达250(摩尔醛)(摩尔铑)- 1 H ^ - 1(p(CO / H 2)= 3.6巴,Ť = 393 K,铑[Rh] = 1毫米,[反式-
2-辛烯] = 640 mM),