4712-38-3Relevant academic research and scientific papers
Butanolysis of B-tris(phenylethynyl)borazine in 1-butanol-dioxane mixed solvent
Yoshizaki, Tamotsu,Watanabe, Haruyuki,Nakagawa, Toshio
, p. 1304 - 1306 (1968)
The alcoholysis of B-tris(phenylethynyl)borazine was investigated in 1-butanol-dioxane mixed solvent in the presence of triethylamine as catalyst. The reaction was followed spectrophotometrically and was found to be first order with respect to the sample as well as the amine concentration. Distinct features were found in the activation parameters, the Arrhenius activation energy being 4.79 kcal/mol and the activation entropy being -45.3 eu. Solvent isotope effect and solvent composition effect on kobsd were also examined. Analyses of these data led to the conclusion that butanol hydrogen-bonded to an amine or to a triethylammonium butylate ion pair attacks the borazine ring in the rate-determining step.
Catalytic conversion of ethanol into an advanced biofuel: Unprecedented selectivity for n-butanol
Dowson, George R. M.,Haddow, Mairi F.,Lee, Jason,Wingad, Richard L.,Wass, Duncan F.
supporting information, p. 9005 - 9008 (2013/09/02)
Taming the beast: Unprecedented selectivity of over 94 % at good (20 %+) conversion was observed for the upgrade of ethanol to the advanced biofuel 1-butanol with a ruthenium diphosphine catalyst (see picture; P orange, Ru blue). Preliminary mechanistic studies indicate that control over the notoriously uncontrolled acetaldehyde aldol condensation is critical for the high selectivity, and evidence was found for an on-metal condensation step. Copyright
Kinetic studies of vapor-phase hydrogenolysis of butyl butyrate to butanol over Cu/ZnO/Al2O3 catalyst
Ju, In Bum,Jeon, Wonjin,Park, Myung-June,Suh, Young-Woong,Suh, Dong Jin,Lee, Chang-Ha
experimental part, p. 100 - 106 (2011/06/17)
Kinetic investigations on the hydrogenolysis of butyl butyrate to butanol over a commercial Cu/ZnO/Al2O3 catalyst were conducted. The catalytic measurements at atmospheric pressure showed that the rate of hydrogenolysis was approximately 0.67 order with respect to butyl butyrate and had a positive effect for hydrogen. The activation energy of this reaction was measured to be about 62 kJ/mol, and D2 isotope studies corroborated that the hydrogenolysis of butyl butyrate proceeds via dissociative adsorption of ester producing C3H7CO and C4H9O fragments. In addition, kinetic studies, interpreted by applying the basis of the Langmuir-Hinshelwood model, suggested that the rate-determining step involves the dissociative adsorption of butyl butyrate. Finally, the rate expression derived in this study provided precise and reasonable fitting results, and an activation energy close to the value obtained from the power law equation.
Study of the mechanism for the hydrolysis of alkoxy(aryl)(phenyl)-λ6- sulfanenitriles, ArPhS(OR)(?N)
Yoshimura, Toshiaki,Dong, Tiaoling,Fujii, Takayoshi,Ohkubo, Masanori,Sakuta, Mikiko,Wakai, Youko,Ono, Shin,Morita, Hiroyuki,Shimasaki, Choichiro
, p. 957 - 965 (2007/10/03)
The hydrolysis of alkoxy(aryl)(phenyl)-λ6-sulfanenitriles in several buffer solutions was found to follow a good pseudo-first-order kinetic equation, giving the corresponding sulfoximides and alcohols (for the case of the hydrolysis of neopentyloxy-λ6-sulfanenitrile, giving a rearranged product, 2-methyl-2-butanol). The dependence of the rate of hydrolysis on the structure of the alkyl group showed the opposite trend to the usual S(N)2 character, i.e. Me +] at pH more than 6.08, and trends to saturate at low pH. According to these kinetic results, a two-step reaction mechanism was proposed which involves a pre-equilibrium protonation on the nitrogen atom of the alkoxy-λ6- sulfanenitriles, followed by a rate-determining C-O bond cleavage via an S(N)2 or S(N)1 mechanism on the alkyl carbon atom depending on the structure of the alkyl group. From a double-reciprocal plot of 1/k(obs) vs. 1/[H+], the pK(a) value and the rate constant of the second reaction of neopentyloxy(diphenyl)-λ6-sulfanenitrile were estimated to be 5.02 and 7.02x10-3 s-1, respectively. The substituent effects on the phenyl group of neopentyloxy(diphenyl)-λ6-sulfanenitrile afforded a large negative p- value (-1.88) for pK(a) and positive one (+1.66) for the second reaction at 25.2 °C. The small negative p-values observed at pH 6.27 for diphenyl(propoxy)-λ6-sulfanenitrile (-0.42) and neopentyloxy(diphenyl)- λ6-sulfanenitrile (-0.26) were found to be the results of a cancellation of those for the opposite trend of the reactions of the pre-equilibrium and the second step. The activation parameters for both the pre-equilibrium and the subsequent reactions were also estimated based on the parameters for the hydrolysis of neopentyloxy(diphenyl)-λ6-sulfanenitrile at pH 6.22 and 2.99. The buffer effect is due to a nucleophilic attack of the buffer base to the alkyl carbon atom of the protonated alkoxy-λ6-sulfanenitriles. The sulfoximide moiety in the protonated λ6-sulfanenitrile is revealed to be a very good leaving group.
