a b s t r a c t 5-(Chloromethyl)furfural (CMF) is rapidly being established as a renewable platform chemical of great promise. The effects of mass transfer, reaction temperature, Hansen solvent parameters, solvent fraction, and initial glucose concentrations on yields of CMF, 5-(hydroxymethyl)furfural (HMF), 2-(hydroxyacetyl) furan (HAF), levulinic acid (LA), and humic matter were investigated in a two-phase system of 6 M HCl and an organic solvent. The ability of the solvent to extract HMF from the aqueous phase is found to be critical to achieving high CMF yields. Effective solvents must possess at least a small degree of Hansen hydrogen bonding capacity, and a high polarity is beneficial. Yields of CMF and HAF decrease with increasing glucose concentration but the yield of HMF is largely unaffected. The maximum productivity of CMF is achieved at a glucose loading of ca. 1.5 M across all solvent fractions tested.
The relative energies of the carbene species in a variety of metathesis reactions catalyzed by Grubbs first-generation catalyst (Cy3P)2Cl2RuCHC6H5 have been determined. High-quality equilibrium data are obtainable by 1H NMR methods. In the case of para-substituted aromatic derivatives (Cy3P)2Cl2RuCH(p-C6H4X), the carbenes are stabilized by donor substituents, and energies may be determined indirectly by use of either NMR data or Hammett correlations, because only electronic effects are operative. Four systems have been characterized by X-ray crystallography. The energies of alkyl-substituted carbenes (Cy3P)2Cl2RuCHR are almost entirely dependent on steric interactions.
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