Synthesis of Carbamoyl Azides from Primary Amines and Carbon Dioxide under Mild Conditions

Abstract

Treatment of amines under a carbon dioxide atmosphere with tetramethylphenylguanidine (PhTMG) and diphenylphosphoryl azide (DPPA) in acetonitrile below 0 degrees C provides carbamoyl azides in high to excellent yields. In addition, epimerization is not observed when optically pure alpha-amino esters are used as substrates.

Synthesis of cyanoformamides from primary amines and carbon dioxide under mild conditions. Synthesis of ceratinamine

“…The reaction conditions (temperature and solvent) previously optimized for the synthesis of carbamoyl azides were successfully applied to the preparation of cyanoformamides. 11 The results of the reaction for several amines under different conditions are shown in Table 1. The yields are generally excellent and in all cases the data refer to isolated and purified products.…”

Carbon dioxide utilization with C–N bond formation: carbon dioxide capture and subsequent conversion

“…NaN 3 and tetramethylphenylguanidine (PhTMG) as a base. 35 The results suggest that a carbamate anion can be eventually transformed into an activated carbonyl species, which in turn could behave as an acylating agent in the presence of an appropriate nucleophile. This proposal can be applied to synthesize oxazolidinones from 1,2-amino alcohols, CO 2 and a phosphorylating agent under basic conditions.…”

Facile One-Pot Synthesis of Carbamoylbenzotriazoles Directly from CO2: Synthesis of Tolbutamide

“…Preferential O-functionalization of the alkoxide oxygen has been accomplished through the addi-tion of metal catalysts, crown ethers, and strong, nonnucleophilic bases, which serve to stabilize the carbamate anion with an increase in the nucleophilicity of the oxygen center. 3 In such a way, carbamate salts have been converted into urethanes, 3,4 substituted ureas, 5 isocyanates, 6 carbamoyl chlorides, 7 S-thiocarbamates, 8 carbamoyl azides, 9 and carbamoyl cyanides. 10 In this communication we report on the use of the oxophilic reagent combination of triphenylphosphine and 1-chlorobenzotriazole (BtCl) 11 for transforming a range of carbamate salts into their corresponding carbamoylbenzotriazoles (Bt ureas, R 2 NCOBt) in good to excellent yield depending on the amine used.…”