Ketones, tetrahydrofurfuryl

A combination of chiral cobalt-catalyst and sodium borohydride was successfully applied to the asymmetric reduction of aromatic ketones. A chiral cobalt complex 164 (5 mol%), prepared from the corresponding salen-type chiral bisketoaldimine and cobalt(II) chloride, catalyzed the reduction of dimethylchromanone 165 in the presence of sodium borohydride (1.5 equiv to ketone) in chloroform, including a small amount of ethanol at -20°C for 120 h to give alcohol 166 92% ee (S ) in 94% yield (Scheme 2.18) [94], Addition of tetrahydrofurfuryl alcohol (THFFA) to the reaction system or the use of pre-modified borohydride, NaBH2(THFFA)2, improved the catalyst activity, that is, using this protocol, the reactions of ketone 165 and... 

THFA = tetrahydrofurfuryl alcohol ketone NaBH4 14 THFA C2H5OH = 100 150 1 2060 450... 

Subsequently to the work on DIBF above, two other aromatic ketones, 2-chlorothioxanthone (CTX) and Michler s ketone (MK) were studied as photosensitizers for the decomposition of onium borates [55, 56]. Each absorbs light at 365 mn and their photochemistry and photophysics are well known. The time dependence of the photopolymerization of tetrahydrofurfuryl acrylate (THFA) in MeCN solution in the presence of CTX with selected onium borates (Figure 12) is shown in Figure 13. The rate of polymerization is dependent on the solvent with the fastest polymerizations observed when the onium borates are used in solvents where they form tight ion pairs. Thus higher rates are observed in the less polar CH2CI2. It is obvious that the rate of photopolymerization without sensitizer is much slower (two orders of magnitude) than that observed for sensitized photoinitiated polymerization. 

Potassium carbonate Tragacanth (Astragalus gummifer) gum Trimethylcyclohexanol 2,2,4-Trimethyl-1,3-pentanediol Zein inks, quick-drying Isopropyl alcohol inks, roll-coating Di isobutyl ketone inks, screen printing Tetrahydrofurfuryl methacrylate inks, specialty Pyrocatechol 2-Pyrrol i done inks, UV-cured... 

Methoxyethanol PPG-3 methyl ether Triglycol monomethyl ether solvent, leather dyes Ethylene glycol isopropyl ether Tetrahydrofurfuryl alcohol solvent, leather finishes s-Butyl acetate Methyl hexyl ketone solvent, leather treating compounds Methyl rapeseedate... 

Optically active cobalt(ii) complexes have been used as catalysts for the enan-tioselective borohydride reduction of aromatic ketones employing pre-modified borohydride. A DKR was observed for the reduction of a 2-ethoxycarbonyl-1-tetralone derivative using pre-modified borohydride arising from NaBH4, tetrahydrofurfuryl alcohol (THFA) and ethanol (Scheme 2.72). 

The monohydric alcohols have densities and surface tensions similar to many aliphatic ketone solvents. The alcoholic solvents afford a wide range of evaporation rates and excellent solvency for various resins and polymeric compositions. The four lowest molecular weight alcohols are completely miscible with water and with most other organic solvents. Tertiary butyl alcohol, diacetone alcohol, furfuryl alcohol, and tetrahydrofurfuryl alcohol are also completely soluble in water. Many of the alcohols form minimum boiling-point azeotropes with water. 

Benzyl alcohol at 155.4°C Tetrahydrofuran, acetone-carbon disulfide mixtures, methyl ethyl ketone Toluene, xylene, methylene chloride, ethylene chloride, perchloroethylene-acetone mixtures, 1,2-dichlorobenzene, tetrahydrofurfuryl alcohol, dioxane, acetone-oarbon disulfide mixtures, cyclopentanone, diisopropyl ketone, mesityl oxide, isophorone, dimethyl-formamide, nitrobenzene, hexamethyl-phosphoramide, tricresyl phosphate Aliphatic and aromatic hydrocarbons, vinyl chloride monomer, alcohols, glycols, aniline, acetone, carboxylic acids, acetic anhydride, esters, nitroparaffins, carbon disulfide, nonoxidizing mineral acids, concentrated alkalies... 

Among the important oxygenated solvents that are not covered above are furan solvents and organic carbonates. Furan solvents of commercial interest include furfuryl alcohol, tetrahydrofuran, and tetrahydrofurfuryl alcohol. They are characterized by strong solvency for some synthetic polymers. Tetrahydrofuran has an evaporation rate between that of acetone and methyl ethyl ketone. Organic carbonate solvents include ethylene and propylene carbonates, diethyl carbonate and dimethyl carbonate, which are good solvents for many polymers. 

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