1801-72-5Relevant articles and documents
Cyclodimerization of isocyanates promoted by one large vertex metallaborane
Ma, Pei,Spencer, James T.
, p. 148 - 152 (2018/06/26)
The 10-vertex Manganese-decaborane [nido-6-Mn(CO)3B9H13][NMe4] was found to act as an efficient catalyst for isocyanate cyclodimerization under photo-irradiation conditions. The reaction yields were comparable with other metal catalyst reported in literature. One of the products was characterized by X-ray crystallographic study and reaction mechanism was also proposed. The results are very encouraging as they represent first examples of a large metallaborane compound to catalyze the cyclodimerization of isocyanates.
Cyclodimerization and cyclotrimerization of isocyanates promoted by one praseodymium benzenethiolate complex [Pr(SPh)3(THF)3]
Wang, He-Ming,Li, Hong-Xi,Yu, Xiang-Yang,Ren, Zhi-Gang,Lang, Jian-Ping
experimental part, p. 1530 - 1535 (2011/04/15)
The cyclotrimerization of aryl isocyanates and the cyclodimerization of alkyl isocyanates initiated by one praseodymium benzenethiolate complex [Pr(SPh)3(THF)3] were investigated. Comparative runs with [Pr(SPh)3(THF)3] and its precursor Pr[(Me 3Si)2N]3 showed that the former has the advantages of a higher selectivity toward isocyanates, easy preparation, low catalyst loading, high conversion as well as mild reaction conditions.
Synthesis of urea derivatives from amines and CO2 in the absence of catalyst and solvent
Wu, Chaoyong,Cheng, Haiyang,Liu, Ruixia,Wang, Qiang,Hao, Yufen,Yu, Yancun,Zhao, Fengyu
experimental part, p. 1811 - 1816 (2011/02/22)
Urea derivatives are obtained in mild to good yield from the reactions of primary aliphatic amines with CO2 in the absence of any catalysts, organic solvents or other additives. To optimize reaction conditions, experimental variables including temperature, pressure, the concentration of amine, reaction time etc. were studied. Satisfactory yields were obtained at the optimized conditions that are comparable to the presence of catalyst and solvent. The preliminary investigation of the reaction mechanism showed that alkyl ammonium alkyl carbamate was quickly formed as the intermediate, and then the final product was formed by the intramolecular dehydration.