How Lewis Acids Catalyze Ene Reactions
How Lewis Acids Catalyze Ene Reactions
复制标题
DOI：
10.1002/ejoc.202101107
复制
发表时间：
2021-10-07
影响因子：
2.8
通讯作者：
Hamlin, Trevor A.
中科院分区：
文献类型：
--
作者：
Tiekink, Eveline H.;Vermeeren, Pascal;Hamlin, Trevor A.
采用密度泛函理论和耦合簇理论研究了不同路易斯酸对丙烯与亲烯试剂丁-3-烯-2-酮反应的催化作用。与未催化的反应相比，所研究的LAs通过降低反应势垒达到12 kcal mol(-1)，有效地加速了烯的反应。我们详细的激活应变和Kohn-Sham分子轨道分析表明，LA催化剂与亲烯试剂的配位通过诱导pi-电子系统的不对称性降低了烯反应的反应势垒，从而增加了不同步性，从而减轻了烯和亲烯试剂的闭合壳层填充pi-轨道之间的高度不稳定的激活应变和泡利排斥。总之，这些发现进一步证明了降低泡利催化概念的普遍性。
The catalytic effect of various Lewis acids (LAs) on the ene reaction between propene (ene) and but-3-en-2-one (enophile) was studied quantum chemically using density functional theory and with coupled-cluster theory. The studied LAs efficiently accelerate the ene reaction by lowering the reaction barrier up to 12 kcal mol(-1) compared to the uncatalyzed reaction. Our detailed activation strain and Kohn-Sham molecular orbital analyses reveal that coordination of a LA catalyst to the enophile decreases the reaction barrier of the ene reaction by inducing an asymmetry in the pi-electronic system, which increases the asynchronicity and hence relieves the otherwise highly destabilizing activation strain and Pauli repulsion between the closed-shell filled pi-orbitals of the ene and enophile. In all, these findings further demonstrate the generality of the Pauli-lowering catalysis concept.