5118-84-3

Upstream product

• 67-56-1 methanol 
• 103-71-9 phenyl isocyanate 
• 1025-36-1 phenyl isocyanate dimer 
• 2603-10-3 N-phenyl methyl carbamate 
• 1091-26-5 methoxytriphenylstannane 

Relevant academic research and scientific papers

Computational tools for mechanistic discrimination in the reductive and metathesis coupling reactions mediated by titanium(IV) isopropoxide

A theoretical study has been carried out at the B3LYP/LANL2DZ level to compare the reactivity of phenyl isocyanate and phenyl isothiocyanate towards titanium(IV) alkoxides. Isocyanates are shown to favour both mono insertion and double insertion reactions. Double insertion in a head-to-tail fashion is shown to be more exothermic than double insertion in a head-to-head fashion. The head-to-head double insertion leads to the metathesis product, a carbodiimide, after the extrusion of carbon dioxide. In the case of phenyl isothiocyanate, calculations favour the formation of only mono insertion products. Formation of a double insertion product is highly unfavourable. Further, these studies indicate that the reverse reaction involving the metathesis of N,N ′-diphenyl carbodiimide with carbon dioxide is likely to proceed more efficiently than the metathesis reaction with carbon disulphide. This is in excellent agreement with experimental results as metathesis with carbon disulphide fails to occur. In a second study, multilayer MM/QM calculations are carried out on intermediates generated from reduction of titanium(IV) alkoxides to investigate the effect of alkoxy bridging on the reactivity of multinuclear Ti species. Bimolecular coupling of imines initiated by Ti(III) species leads to a mixture of diastereomers and not diastereoselective coupling of the imine. However if the reaction is carried out by a trimeric biradical species, diastereoselective coupling of the imine is predicted. The presence of alkoxy bridges greatly favours the formation of the d,l (±) isomer, whereas the intermediate without alkoxy bridges favours the more stable meso isomer. As a bridged trimeric species, stabilized by bridging alkoxy groups, correctly explains the diastereoselective reaction, it is the most likely intermediate in the reaction.

Reaction of isocyanates with alkyl N-phenylcarbamates

Alkyl N-phenylcarbamates accelerate thermolysis of isocyanates by forming with the latter at the first stage of the thermolysis a donor-acceptor complex. The accelerative effect of the carbamates is enhanced by increasing electron-donor power of substituents in the carbamates and increasing electron-donor power of the isocyanates.

INVESTIGATION OF CATALYZED TRANSFORMATIONS OF PHENYL ISOCYANATE IN THE PRESENCE OF PROTON-DONATING REAGENTS

The transformation of phenyl isocyanate in chlorobenzene in the presence of proton-donating reagents, catalyzed by the sodium acetate-dibenzo-18-crown-6 system, takes place in stages with the formation of triphenyl isocyanurate.The intermediate products in the polyaddition of the isocyanate are urethane and an allophanate.