Poly(Ethylene Glycol) and Derivatives as Phase Transfer Catalysts

An efficient method for Knoevenagel condensation: a facile synthesis of 5-arylidenyl 2,4-thiazolidinedione

“…The PEGs are hydrophilic, thermally stable, non-toxic and protic solvents (26) having aprotic etheral sites and are able to dissolve most of the organic and some inorganic solutes (27). This class of oligomers are established as green/cleaner host recyclable solvents (28) and also functions as safer phase transfer catalyst (29,30). Different aromatic aldehydes and 2,4-thiazolidinedione in PEG-300 were heated on oil bath at 100Á 1208C (2a Á g).…”

Integrating Microwave‐Assisted Synthesis and Solid‐Supported Reagents

“…For example, a number of publications have described the use of soluble polymers, such as PEG, to serve as both phase-transfer reagents and the solvent for a reaction [105][106][107][108][109][110][111][112][113][114][115] . PEG systems of low-average-molecular weight offer a number of unique attractions because of their relatively low-melting points (MW 400-800) 45-47 • C and facile separation from small organic compounds.…”

Application of polyethylene glycol-based aqueous biphasic reactive extraction to the catalytic oxidation of cyclic olefins

“…More recently, we have investigated the partitioning and separation of organic hydrocarbon species [10][11][12][13] and metal ions [14][15][16][17] in ABS to obviate the need for volatile organic solvents (VOCs) in liquid/liquid partitioning. Other researchers have now started to examine low molecular weight liquid polyethylene glycol (PEG) as new solvent systems for reactive chemistry, e.g., for osmium tetroxide catalyzed asymmetric dihydroxylation [18], polyoxometallate catalyzed aerobic oxidation [19], hydrolysis reactions [20,21], and as alternative phase transfer catalysts (PTC) [22]. ABS, on the other hand, have been largely ignored as "green reaction media" for chemical reactions, although a certain number of enzyme hydrolysis bioconversion reactions have been conducted in ABS [7].…”