Observation of guanidine–carbon dioxide complexation in solution and its role in the reaction of carbon dioxide and propargylamines

Abstract

The first observation of guanidine–CO₂ ‘activation’ complexes in solution using ATR-FTIR is reported. While cyclic guanidines TBD and MTBD form stable and detectable complexes with CO₂, other guanidines and tertiary amines do not. Correlation with the catalytic activity of these amines/guanidines in the reaction between CO₂ and propargylamines indicated that the basicity of the catalyst, rather than its ability to form complexes with CO₂, is the origin of catalytic activity.