Synthesis of Isoidide through Epimerization of Isosorbide using Ruthenium on Carbon

A highly efficient procedure for obtaining resin-grade isoidide through catalytic epimerization of isosorbide using a ruthenium-on-carbon (Ru/C) catalyst is reported. A comprehensive reaction-parameter variation study involving substrate concentration, catalyst (type of metal, support, and loading), initial pH value, hydrogen pressure, solvent, and reaction temperature demonstrates that superior performance and high selectivity can be achieved. Epimerization of isosorbide in water (pH 8) at 220¿°C, under 40 bar of hydrogen, and using a Ru/C catalyst (5¿% Ru) for 2 h results in a thermodynamic equilibrium mixture containing 55¿% isoidide, 40¿% isosorbide, and 5¿% isomannide. In comparison with previously reported nickel-based catalysts, the Ru/C catalyst is advantageous because it is highly active (as low as 360 ppm Ru) and recyclable. High purity isoidide is obtained by high-vacuum distillation of an equilibrium mixture on a 200 g scale. The high substrate loading (50 wt¿% in water), high selectivity, and the possibility for substrate reuse makes this procedure highly atom efficient and therefore, highly attractive for industrial us

Synthesis of Isoidide through Epimerization of Isosorbide using Ruthenium on Carbon

A highly efficient procedure for obtaining resin-grade isoidide through catalytic epimerization of isosorbide using a ruthenium-on-carbon (Ru/C) catalyst is reported. A comprehensive reaction-parameter variation study involving substrate concentration, catalyst (type of metal, support, and loading), initial pH value, hydrogen pressure, solvent, and reaction temperature demonstrates that superior performance and high selectivity can be achieved. Epimerization of isosorbide in water (pH 8) at 220¿°C, under 40 bar of hydrogen, and using a Ru/C catalyst (5¿% Ru) for 2 h results in a thermodynamic equilibrium mixture containing 55¿% isoidide, 40¿% isosorbide, and 5¿% isomannide. In comparison with previously reported nickel-based catalysts, the Ru/C catalyst is advantageous because it is highly active (as low as 360 ppm Ru) and recyclable. High purity isoidide is obtained by high-vacuum distillation of an equilibrium mixture on a 200 g scale. The high substrate loading (50 wt¿% in water), high selectivity, and the possibility for substrate reuse makes this procedure highly atom efficient and therefore, highly attractive for industrial us

Conversion of polyhydroxybutyrate (PHB) to methyl crotonate for the production of biobased monomers

Within the concept of the replacement of fossil with biobased resources, bacterial polyhydroxybutyrate (PHB) can be obtained from volatile fatt y acids (VFAs) from agro-food waste streams and used as an intermediate toward attractive chemicals. Here we address a crucial step in this process, the conversion of PHB to methyl crotonate (MC), which can be converted via cross- metathesis w ith ethylene to methyl acrylate and propylene, two important monomers for the plastics industry. The conversion of PHB to MC proceeds via a thermolysis of PHB to crotonic acid (CA), followed by an esterification to MC. At pressures below 18 bar, the thermolysis of PHB to CA is the rate-determining step, where above 18 bar, the esterification of CA to MC becomes rate lim- iting. At 2008C and 18 bar, a full conversion and 60% selectiv ity to MC is obtained. This conversion circumvents processing and application issues of PHB as a polymer and allows PHB to be used as an intermediate to produce biobased chemicals

Process for the production of methacrylic acid

Disclosed is a method of making methacrylic acid, or a carboxylic derivative thereof, from itaconic acid, isomers, or precursors thereof. A starting material comprising an acid selected from the group consisting of itaconic acid, citraconic acid, mesaconic acid, citric acid, aconitic acid, isocitric acid and mixtures thereof, is subjected to contact with 0.1 eq. to 3.0 eq. of a base, at a temperature of 150°C to 350°C, under the influence of a transition metal-containing heterogeneous catalyst. A better yield at lower temperatures is achieved

Simultaneous production of biobased styrene and acrylates using ethenolysis

Phenylalanine (1), which could be potentially obtained from biofuel waste streams, is a precursor of cinnamic acid (2) that can be converted into two bulk chemicals, styrene (3) and acrylic acid (4), via an atom efficient pathway. With 5 mol% of Hoveyda–Grubbs 2nd generation catalyst, 1 bar of ethylene, and using dichloromethane as solvent, cinnamic acid (2) can be converted to acrylic acid and styrene at 40 °C in 24 h with 13% conversion and 100% selectivity. Similar results are obtained using cinnamic acid esters (methyl, ethyl and n-butyl) as substrates and optimisation leads to higher conversions (up to 38%). For the first time, cross-metathesis of these types of electron deficient substrates was achieve

Selective oxidative decarboxylation of amino acids to produce industrially relevant nitriles by vanadium chloroperoxidase

Industrial nitriles from biomass: Vanadium-chloroperoxidase is successfully used to transform selectively glutamic acid into 3-cyanopropanoic acid, a key intermediate for the synthesis of bio-succinonitrile and bio-acrylonitrile, by using a catalytic amount of a halide salt. This clean oxidative decarboxylation can be applied to mixtures of amino acids obtained from plant waste streams, leading to easily separable nitriles

Bio-derived olefin synthesis

Disclosed is a method for the combined synthesis of at least two vinylic monomers, at least one of which being an acrylic compound, comprising subjecting a monoconjgated alkene-1-carboxylic compound to reaction with a C2-C4 alkene under conditions of olefin cross-metathesis. The invention is particularly useful for extracting value from protein side streams. Upon protein hydrolysis, suitable amino acids (preferably phenylalanine or tyrosine) are subjected to reductive amination so as to form the corresponding alkene-1-carboxylic acid. Preferably after esterification and separation, this is used in cross-metathesis for the concomitant production of styrene resp. hydroxy styrene, and acrylates. The invention is applicable more widely, to the synthesis of olefins on the basis of carbohydrates, naturally occurring phenolic components, natural protein resources, or amino acids obtained from fermentations

Method of making isoidide

Disclosed is a process for the preparation of isoidide from isosorbide. An aqueous solution of isosorbide is subjected to epimerization in the presence of hydrogen under the influence of a catalyst comprising ruthenium on a support, preferably a carbon support. The process of the invention can be conducted using a relatively low hydrogen pressure, and leads to a desired distribution of epimers, favoring isoidide over isomannide and isosorbide