the reaction of carbon dioxide with terminal epoxides or aziridines at ambient temperature and 1 bar carbon dioxide pressure. Only 1.0 mol% of both (salen)CoI 3g and phosphorane 4d are required for cyclic carbonate synthesis, and the catalyst loading could even be lowered down to 0.1 mol%. Under this condition, no polycarbonate formation is detected by NMR analysis. It is proposed that the high efficiency
N-Heterocyclic Olefins as Robust Organocatalyst for the Chemical Conversion of Carbon Dioxide to Value-Added Chemicals
作者:Vitthal B. Saptal、Bhalchandra M. Bhanage
DOI:10.1002/cssc.201600467
日期:2016.8.9
activity of N‐heterocyclic olefins (NHOs) as a newly emerging class of organocatalyst is investigated for the chemical fixation of carbondioxide through reactions with aziridines to form oxazolidinones and the N‐formylation of amines with polymethylhydrosiloxane (PMHS) or 9‐borabicyclo[3.3.1]nonane (9‐BBN) as the reducing agent under mild conditions. The exocyclic carbon atoms of NHOs are highly nucleophilic
5-Aryl-2-oxazolidinones have been synthesized readily by the elimination of dimethylamine from the corresponding (2-hydroxyethyl)ureas. The ureas are obtainable by the photoreaction of tetramethylurea with para-substituted benzaldehydes (Method A) or with para-substituted methyl benzoates (Method B). The electronic character of the substituent on the benzene ring determines which method is suitable
The catalytic potential of a large series of easily available metal carbamates (based on thirteen different non-precious metal elements) was explored for the first time in the coupling reaction between 2-aryl-aziridines and carbondioxide, working under solventless and ambient conditions and using tetraalkylammonium halides as co-catalysts. The straightforward synthesis of novel [NbCl3(O2CNEt2)2],