Synthesis of carbamates from carbon dioxide promoted by organostannanes and alkoxysilanes

Abstract

A cooperative methoxy transfer between orthosilicate esters and organotin oxides was developed for the synthesis of various N-alkyl and N-aryl carbamates from carbon dioxide in up to 97% isolated yield. The reaction is highly selective and Nalkylated amines are not observed. Density functional theory calculations of the reaction were performed and, together with NMR observations, a plausible mechanism featuring the catalytic regeneration of dialkyltin dialkoxide is proposed.

Efficient Activation of CO2 over Ce-MOF-derived CeO2 for the Synthesis of Cyclic Urea, Urethane, and Carbamate

“…The homogeneous titanium complex has also been found effective for synthesizing cyclic urea from alkyl ammonium carbamate . Several heterogeneous catalysts, including Au decorated in the polymer matrix, metal oxides (including CeO 2 ), silica-based catalysts, and MOF, have been reported for this reaction. − Sn and Ni metal complexes have been utilized for carbamate synthesis. − Moreover, CeO 2 has also been explored for carbamate synthesis …”

Highly Efficient Synthesis of Alkyl N-Arylcarbamates from CO2, Anilines, and Branched Alcohols with a Catalyst System of CeO2 and 2-Cyanopyridine

“…Alkyl N -arylcarbamates have received much attention due to their application in the manufacture of polyurethanes, which are an important class of polymeric materials with a market size of 54 billion USD in 2015. − At present, the commercial processes for production of alkyl N -arylcarbamates usually require the use of toxic and hazardous reagents such as phosgene and CO, − and many efforts have been made toward development of environmentally friendly alternative methods including aminolysis of organic carbonates, ,,− alcoholysis of diaryl ureas, and coupling reaction of organic carbonates and diaryl ureas . As an alternative to the methods above, reactions of CO 2 as a carbonyl source with anilines and highly reactive reagents such as alkylhalides, − metal alkoxides, − and silicate esters − have been intensively investigated for the synthesis of arylcarbamates.…”

CO2 Derivatives of Molecular Tin Compounds. Part 2: Carbamato, Formato, Phosphinoformato and Metallocarboxylato Complexes

“…In the perspective of an industrial development, the authors have demonstrated the possibility of regenerating and re-using the dialkyltin(IV) dialkoxides, by using an excess of dimethylcarbonate. Shortly after, in a new study, the same group improved the reaction yield (up to 97%) by combining with dialkyltin oxide, used as a tin precursor, tetraalkyl orthosilicates, which promote the generation of dialkyltin(IV) dialkox-ides [33]. This positive effect had been initially shown for the tin-promoted synthesis of organic carbonates from carbon dioxide and alcohols [34].…”

“…Additionally in 1965, the study was then extended to bis(trialkyltin) oxides, which react exothermically with isocyanates to lead to trialkyltin N-trialkylstannylcarbamates (Scheme 8) [36]. used as a tin precursor, tetraalkyl orthosilicates, which promote the generation of dialkyltin(IV) dialkoxides [33]. This positive effect had been initially shown for the tin-promoted synthesis of organic carbonates from carbon dioxide and alcohols [34].…”

“…Inorganics 2021, 9, x FOR PEER REVIEW 5 of 33 used as a tin precursor, tetraalkyl orthosilicates, which promote the generation of dialkyltin(IV) dialkoxides [33]. This positive effect had been initially shown for the tin-promoted synthesis of organic carbonates from carbon dioxide and alcohols [34].…”