In this technique, a hydrated metal salt (such as a nitrate or a chloride) is dissolved in a solvent (such as water, ethanol, or half-water/half-ethanol), to which an epoxide (such as propylene oxide or epichlorohydrin) is added dropwise. The metal salts exist as some sort of aquo complex in solution (that is, they have water ligands attached to them). The epoxide then acts as a proton scavenger, stealing a proton away from the metal complex and protonates itself, resulting in an irreversible ring-opening reaction. The pH of the system, in turn, gently increases, and aquo-hydroxy metal complexes form. These species, which contain M-OH sites, can then condense together to form metal-oxygen-metal bridges (similar to the way Si-OH groups condense together to form silicon-oxygen-silicon bridges)–the necessary connectivity for producing a metal oxide gel. Upon supercritical drying of the resulting gel, a metal oxide aerogel is produced.
Xue, F.; Liu, Z. Q.; Wang, Y. J.; Zhu, H. Q.; Wan, N. W.; Zheng, Y. G. Efficient synthesis of (S)-epichlorohydrin in high yield by cascade biocatalysis with halohydrin dehalogenase and epoxide hydrolase mutants. Catal. Commun. 2015, 72, 147-149.
(S)-(+)-Epichlorohydrin is utilized for the synthesis of macquarimicins and hydroxyisoxazolidines and (+)-cis-sylvaticin, which is a potential antitumor agent. It is used to synthesize inhibitors of fatty acid oxidation as potential metabolic modulators. It acts as a solvent for natural and synthetic resins, gums, cellulose esters and ethers, paints, varnishes, nail enamels, lacquers and cement for celluloid. It is also used as a stabilizer and also useful as a bifunctional alkylating agent with the potential to form DNA cross-links.
Epichlorohydrin is used in the manufacture of polyamines and polyquaternary ammonium salts, as flocculents in water and wastewater treatment. It is used in the synthesis of surface active agents for washing products and toiletries. Polyamine-epichlorohydrin resin is used in paper industry to improve paper wet-strength. It acts as a chemical intermediate and widely used in the manufacture of epoxy resins, epichlorohydrin elastomers and polyamide-epichlorohydrin resins.
Xue, F.; Liu, Z. Q.; Wang, Y. J.; Zhu, H. Q.; Wan, N. W.; Zheng, Y. G. Efficient synthesis of (S)-epichlorohydrin in high yield by cascade biocatalysis with halohydrin dehalogenase and epoxide hydrolase mutants. Catal. Commun. 2015, 72, 147-149.Gajare, V. S.; Khobare, S. R.; Malavika, B.; Rajana, N.; Rao, B. V.; Kumar, U. K. S. A short diastereoselective synthesis of cis-(2S,4S) and cis-(2R,4R)-4-hydroxyprolines. Tetrahedron Lett. 2015, 56 (24), 3743-3746.
R., Activity-Based Protein Profiling Reagents for Protein Arginine Deaminase 4 (PAD4): Synthesis and in vitro Evaluation of a Fluorescently Labeled Probe.
B., Synthesis of azide-alkyne fragments for click' chemical applications; formation of oligomers from orthogonally protected trialkylsilyl-propargyl azides and propargyl alcohols.
Glycerol is a co-product of biodiesel produced on a large scale. The conversion of glycerol into other building block chemicals is of great interest because glycerol is otherwise hard to dispose of. Dow and Solvay are building glycerol-to-epichlorohydrin (GTE) plants in Shanghai and Thailand, respectively. In Dow's process, glycerol is dichlorinated with hydrogen chloride with the help of a carboxylic acid catalyst. The mixture of dichlorohydroxypropanes is treated with base to form epichlorohydrin.
Mesoporous Zr-MCM-41 and Ti-MCM-41 have been synthesized at room temperature by sol-gel method using templates possessing high surface area, good thermal stability and maximum M4+ incorporation varying SiO2:ZrO2/TiO2 ratios. The salient feature is synthesis of the materials at room temperature. Both the synthesized materials have been characterized for elemental analysis by ICP-AES, XRD, TEM, SEM, EDX, surface area (by BET method), pore volume and pore distribution (BJH method), UV-DRS, FTIR and TGA. Further, the catalytic potential of both the materials have been compared by studying epoxidation as a model reaction using H2O2 as an oxidant in the conversion of allyl chloride to selectively produce epichlorohydrin in a single step at room temperature by varying several parameters such as catalyst amount, reaction time, types of oxidants including catalyst regeneration and reuse.
R.; Lober, S.; Hubner, H.; Gmeiner, P., Click chemistry on solid phase: parallel synthesis of -benzyltriazole carboxamides as super-potent G-protein coupled receptor ligands.