Mechanisms of CO2 Incorporation into Propargylic Amine Catalyzed by Ag(I)/Amine Catalysts

Ruming Yuan; Shuhua Xu; Gang Fu

doi:10.1021/acs.joc.8b01767

Mechanisms of CO₂ Incorporation into Propargylic Amine Catalyzed by Ag(I)/Amine Catalysts

J Org Chem. 2018 Oct 5;83(19):11896-11904. doi: 10.1021/acs.joc.8b01767. Epub 2018 Sep 18.

Authors

Ruming Yuan¹, Shuhua Xu¹, Gang Fu¹

Affiliation

¹ State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, National Engineering Laboratory for Green Chemical Productions of Alcohols, Ethers, and Esters, and Department of Chemistry, College of Chemistry and Chemical Engineering , Xiamen University , Xiamen 361005 , China.

PMID: 30189725
DOI: 10.1021/acs.joc.8b01767

Abstract

Density functional theory calculations are carried out to explore the detail mechanisms of CO₂ incorporation into propargylic amine catalyzed by Ag(I)/amine catalysts. Our calculations reveal that the whole reaction involves Lewis acid catalysis and Lewis base catalysis stages, and the outcomes of this reaction critically depend on the basicity of amine. A weaker base (i.e., DABCO) makes the Ag center more acidic, thus favoring the Lewis acid catalysis, resulting in benzoxazin-2-one. However, the following rearrangement of benzoxazin-2-one requires a stronger base (i.e., DBU) to stabilize its deprotonated form. Thus, the product selectivity could be subtly tuned by the choice of amine and the condition control, consistent with the experimental observations.