AgI/TMG‐Promoted Cascade Reaction of Propargyl Alcohols, Carbon Dioxide, and 2‐Aminoethanols to 2‐Oxazolidinones

• Published in: Chemphyschem Vol. 18; no. 22; pp. 3182 - 3188
• Main Authors: Li, Xue‐Dong, Song, Qing‐Wen, Lang, Xian‐Dong, Chang, Yao, He, Liang‐Nian
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 17.11.2017
• Subjects: Alcohol; Alcohols; C1 building blocks; Carbon dioxide; carbon dioxide chemistry; Cascade chemical reactions; Chemical bonds; cyclization; homogeneous catalysis; Hydrogen bonds; Ketones; NMR; Nuclear magnetic resonance; Propargyl alcohol; synthetic methods
• ISSN: 1439-4235; 1439-7641
• DOI: 10.1002/cphc.201700297

Chemical valorization of CO2 to access various value‐added compounds has been a long‐term and challenging objective from the viewpoint of sustainable chemistry. Herein, a one‐pot three‐component reaction of terminal propargyl alcohols, CO2, and 2‐aminoethanols was developed for the synthesis of 2‐oxazolidinones and an equal amount of α‐hydroxyl ketones promoted by Ag2O/TMG (1,1,3,3‐tetramethylguanidine) with a TON (turnover number) of up to 1260. By addition of terminal propargyl alcohol, the thermodynamic disadvantage of the conventional 2‐aminoethanol/CO2 coupling was ameliorated. Mechanistic investigations including control experiments, DFT calculation, kinetic and NMR studies suggest that the reaction proceeds through a cascade pathway and TMG could activate propargyl alcohol and 2‐aminoethanol through the formation of hydrogen bonds and also activate CO2. Heterocycle promotion: An Ag2O/TMG (1,1,3,3‐tetramethylguanidine) promoted substrate‐driven and divergent route leads to a variety of heterocycles from propargyl alcohols, CO2, and 2‐aminoethanols with turnover numbers up to 1260. The reaction proceeds through a cascade pathway with α‐alkylidene cyclic carbonate as the intermediate.