Catalytic Effects in Isocyanate Reactions

Farkas, A.; Mills, Gregory

doi:10.1016/s0360-0564(08)60290-4

Cited by 45 publications

(22 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Amine Nos. 1,2,5,6,9,12,13,14, and 15 have been previously studied in conjunction with isocyanate reactions or acid gas removal, or are structurally related to amines which have been used in such studies (Sykes, 1976;Bratzler et al, 1976Bratzler et al, , 1977Bozzelli et al, 1978: Correll andFriedli, 1980;Farkas and Mills, 1962). The rest of the amines were selected in order to broaden the pKB range of the study.…”

Section: Resultsmentioning

confidence: 99%

“…1987 In general the results of this study are analogous to those reported earlier for the reaction of isocyanates with hydroxyl compounds. A mechanism analogous to Equations (1) and (2) If the concentration of "complex" is assumed constant at a steady state value, the rate of reaction can be described by the equation: Staley and Beauchamp, 1974 (c) Farkas and Mills, 1962 (d) Christensen et al, 1976 (e) Pearson and Williams, 1953 a Huber, 1967 (g) Determined in batch reactor. Values in parentheses were determined in a continuous flow reactor (h) Flow reactor data determined in a previous study (Ernst and Chen, 1987) (i) I-Methylindole and I-Methyl-2-piperidone (Nos.…”

Section: Resultsmentioning

confidence: 99%

“…The fact that not all of the data in Figure 2 fell on the same line is evidence that a mechanism involving proton transfer did not predominate and consequently did not mask a second mechanism in which factors other than basicity are important. Farkas and Mills (1962) argued that a proton transfer mechanism is the base-catalyzed reaction of isocyanates with thiols was insignificant.…”

Section: Resultsmentioning

confidence: 99%

“…Catalysis of reactions involving isocyanates by tertiary amines has been studied extensively (see for example Farkas and Mills, 1962); this subject is of theoretical interest because of the influence of catalyst structure on reaction rates. Both the basic strength @KB) and steric hindrance of tertiary amines play a role in determining catalytic activity.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Hydrolysis of carbonyl sulfide: Comparison to reactions of isocyanates

1990

View full text Add to dashboard Cite

The hydrolysis of carbonyl suflfide (COS), catalyzed by tertiary amines, was studied in a gas‐liquid reactor at ambient conditions. Rate constants determined in a batch reactor were similar to those determined in a continuous flow reactor. A Bronsted plot of the reaction data over the amine basicity range, 0 < pKB < 14, suggested that both amine basicity and steric factors determine catalytic behavior. The reaction data suggest a mechanism analogous to one used to explain the base catalyzed reaction of isocyanates with hydroxyl compounds. The mechanism would involve complexation of COS with amine followed by hydrolysis of the complex.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Hydrolysis of carbonyl sulfide: Comparison to reactions of isocyanates

1990

View full text Add to dashboard Cite

show abstract

“…Owing to this commercial interest, the literature concerning this reaction is voluminous [3,4], but only few of them are on the transition state (TS) of the reaction. Recently, the CNDO/BW method has been employed to study the TS of the reaction [5].…”

Section: Introductionmentioning

confidence: 99%

Theoretical study on the reaction mechanism of the alcoholysis of isocyanates

Tang

1992

Int J of Quantum Chemistry

View full text Add to dashboard Cite

In this paper, the reactions of HNCO or CH3NCO with methanol have been studied using the ab initio MO method. The geometries of the reactants and products have been optimized by the energy gradient method. The calculated results are in accordance with experiment. Using Powell's method, by the minimization of the Euclidean norm aof the gradient, the structures of the transition state (TS) for the two reactions were obtained. The structures have been further confirmed as TS by finding that there is one and only one negative eigenvalue for their force constant matrix. The imaginary vibration mode corresponding to the TS was also discussed. The calculated activation barriers of these two reactions are 96.02 and 95.13 kJ/mol, respectively. It can be concluded that the alcoholysis reaction of isocyanate is a nucleophilic addition reaction with methanol as an electronic donor and isocyanate as an acceptor and that the hydroxyl hydrogen of CH30H plays an important role in the reaction.

show abstract