羰基化合物及其与卤代烃在CeCl~3/萘锂试剂作用下的反应

用萘锂(LiNp)还原无水CeCl~3制得的活性金属铈(Ce^*)在与羰基化合物的反应中,与用相同方法制得的Nd^*相比,表现出更高的反应活性。Ce^*与羰基化合物反应经水解可生成相应的醇,频哪醇和烯烃,其选择性不仅与反应时间和温度有关,而且还与羰基化合物的种类以及CeCl~3:LiNp:RCOR'的摩尔比有关。初步研究了Ce^*作用下的酮和一些卤代烃的反应。

Reaction of anhydrous CeCl~3 reduced by lithium naphthalide with carbonyl compounds and halohydrocarbon

The active cerium metal (Ce^*) prepared by the reduction of anhydrous CeCl~3 with LiNp (Lithium Naphthalide) shows higher reactivity in its action with carbonyl compounds than Nd^* obtained by the same reduction method. The reaction of Ce^* with carbonyl compounds, followed by hydrolysis, produces the corresponding alcohols, pinacols and alkenes depending not only on the reaction time and temperature but also on the nature of the carbonyl compounds and the molar ratio of the Ce^*:RCOR'. Interestingly, the effect of the different molar ratio of CeCl~3:LiNp also shows different reactivity and selectivity oof low valent Ce species. In addition, the reaction of ketones with halohydrocarbon promoted by active cerium metal was also studied.