Svatunek Dennis, Hansen Thomas, Houk Kendall N, Hamlin Trevor A
Department of Theoretical Chemistry, Amsterdam Institute of Molecular and Life Sciences (AIMSS), Amsterdam Center for Multiscale Modeling (ACMM), Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081 HV, Amsterdam, The Netherlands.
Institute of Applied Synthetic Chemistry, TU Wien (Vienna University of Technology), A-1060, Vienna, Austria.
J Org Chem. 2021 Mar 5;86(5):4320-4325. doi: 10.1021/acs.joc.0c02963. Epub 2021 Feb 12.
The mechanism of the Lewis base F catalyzed 1,3-dipolar cycloaddition between CO and nitrilimines is interrogated using DFT calculations. F activates the nitrilimine, not CO as proposed in the literature, and imparts a significant rate enhancement for the cycloaddition. The origin of this catalysis is in the strength of the primary orbital interactions between the reactants. The Lewis base activated nitrilimine-F has high-lying filled FMOs. The smaller FMO-LUMO gap promotes a rapid nucleophilic attack and overall cycloaddition with CO.
利用密度泛函理论(DFT)计算研究了路易斯碱F催化的CO与腈亚胺之间的1,3-偶极环加成反应机理。F激活了腈亚胺,而非如文献中所提出的激活CO,并显著提高了环加成反应的速率。这种催化作用的起源在于反应物之间主要轨道相互作用的强度。路易斯碱活化的腈亚胺-F具有较高能级的占据分子轨道(FMOs)。较小的FMO-最低未占分子轨道(LUMO)能隙促进了亲核进攻的快速进行以及与CO的整体环加成反应。