Phenylacetaldehyde, polymerization

When pure phenylacetaldehyde was treated under the conditions that resulted in the conversion of benzyl alcohol to toluene and 2-phenyl-ethanol, the phenylacetaldehyde polymerized and no identifiable reaction products were secured. More information on this matter was obtained with the substituted benzyl alcohol, benzhydrol. Benzhydrol, on treatment with synthesis gas, gives an almost quantitative yield of diphenyl-methane. The hydrocarbon may be formed by decarbonylation of the intermediate diphenylacetaldehyde, or by direct hydrogenolysis of the alcohol ... 

T he initiating effect of phenylacetaldehyde on the copolymerization of unsaturated polyesters with vinyl monomers has been described (9). The copolymerization proceeds at approximately the same rate as with the usual peroxide catalysts, but the reaction is much less exothermic hence, the effects of too rapid a polymerization such as fissures, bubble formation, and volume contraction do not occur. Investigation of a series of compounds of the benzene family showed that only enolizable phenyl-keto compounds were initiators (7). 

Styrene oxide reacted rapidly but gave no volatile material, perhaps because of aldol polymerization of phenylacetaldehyde (the probable initial product). Norbomene oxide gave no detectable reaction, either because endo attack of bromide is especially unfavorable, or because the bromohydrin salt has no geometrically accessible alternative other than to return to epoxide. 

Liskamp has reported the synthesis and the screening in asymmetric catalysis of a library of polymer-supported peptidosulfonamide [147]. Rt) or (5 -pyrrolydines 222 prepared in six steps from D or Z-tartaric acid were anchored onto Argonaut resin (0.41 mmol/g) to afford the corresponding supported pyrrolidines 223 (Scheme 91). The polymeric peptidosulfonamides 224 and 225 were then synthesized in four steps from the immobilized pyrrolidines 223. The different chiral polymers were tested in the titanium-mediated diethylzinc addition to benzaldehyde,/ -chlorobenzaldehyde, cyclohexanecarboxaldehyde and phenylacetaldehyde. Both yield and ee were very low with all these supported-ligands for the enantioselective reaction with the two aliphatic aldehydes. With aromatic aldehydes, the best results were observed with both leucine-derived supported peptidosulfonamides 224d and 225d. 

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