Betaine Catalysis for Hierarchical Reduction of CO<sub>2</sub>with Amines and Hydrosilane To Form Formamides, Aminals, and Methylamines
作者:Xiao-Fang Liu、Xiao-Ya Li、Chang Qiao、Hong-Chen Fu、Liang-Nian He
DOI:10.1002/anie.201702734
日期:2017.6.19
sustainable organocatalyst, glycine betaine, was developed for the reductive functionalization of CO2 with amines and diphenylsilane. Methylamines and formamides were obtained in high yield by tuning the CO2 pressure and reaction temperature. Based on identification of the key intermediate, that is, the aminal, an alternative mechanism for methylation involving the C0 silyl acetal and aminal is proposed. Furthermore
The four-electron reduction of CO2 in the presence of secondary aromatic amines is described for the first time to access aminals. Under metal-free hydrosilylation conditions, the four C-O bonds of CO2 are cleaved, and the organocatalysts are able to balance the reactivity of CO2 to promote the selective formation of two C-N and two C-H bonds. The methodology enables the formation of various symmetrical and unsymmetrical aminals.
Weerman, Recueil des Travaux Chimiques des Pays-Bas, 1906, vol. 25, p. 263