Substituted polymethylene

Aliphatic carbon main chains with small side groups (substituted polymethylene chains)... 

Abstract Novel vinyl polymers were synthesized from 1,1- or 1,2-disubstituted and 1,1,2-trisubstituted ethylenes by radical polymerization. The polymers obtained consist of a rigid chain structure on account of the bulky side groups compared with flexible poly(monosubstituted ethylene)s. The substituted polymethylenes obtained from 1,2-disubstituted ethylenes such as fumaric and maleic derivatives were revealed to have new properties different from ordinary vinyl polymers. Radical polymerization behaviors of these multi-substituted ethylenes and some properties of the resulting polymers were investigated. 

On the other hand, cis or trans and cyclic 1,2-disubstituted ethylenes have been well-known till 1980 to be not homopolymerized with a radical initiator owing to the much more increased steric effect of the substituents except for a few exceptions, e.g., fluoro-substituted ethylenes and cyclic derivatives, vinylene carbonate (VCa), maleic anhydride (MAn), yV-substituted maleimides (RMI), and acenaphthylene. However, if 1,2-disubstituted and tri- or tetra-substituted ethylenes can homopolymerize, the polymers with a substituted polymethylene structure, which is different from the above polyethylenes, would be obtained (eqs. 1 and 2), i.e., the polymers would be less flexible (more rigid), and have higher glass transition temperatures than those for the polyethylenes, although their processabilities would decrease. 

The poly(RMI)s were confirmed to consist of substituted polymethylene structure by IR and NMR spectroscopies. The poly(RMI)s are soluble in many organic solvents, and a thin and tough film is obtained from the chloroform solution. It was confirmed that poly(RMI) with various length /7-alkyl groups showed a high 7k from 97 C to 185 C respective to the length of the alkyl chain [47], but the polymers with bulky yv-substituents such as tert-alkyl groups did not melt and did not show any transition temperatures... 

On the other hand, because TDM and dimethylsulfoxonium methylide 11 react with organoborane in a similar mechanism (formation of borate followed by 1,2-migration), organoborane-initiated copolymerization of TMD with 11 proceeded to give poly(TMSmethylidene-co-methylene), which is a partially TMS-substituted polymethylene [69]. Although the composition of TMSCH in the products was lower than that expected from the feed ratio of [TDM]/[11], oligomers with a relatively narrow MWD were obtained as shown in Scheme 47. 

A mixture of polymethylene glycols of the type (CH20) ,xH20 where n is 6- 50. It is a white, amorphous powder having the odour of meth-anal, m.p. I20-130°C. The commercial product contains 95% methanal and is obtained in while flocculent masses when solutions of methanal are evaporated or allowed to stand. When heated it is converted to methanal. Used as a convenient solid substitute for methanal. 

Fig. 11 Plots of log EM vs number of bridge methylenes for the formation of catechol, resorcinol, and hydroquinone polymethylene ethers by intramolecular nucleophilic substitution in 99% Me2SO. (Reproduced with permission from Dalla Cort et al., 1980)...

The simple pictorial interpretation of the gem-dimethyl effect presented by Dale (1963, 1966) was based on the idea that the ease of cyclisation depends more on the conformation of the open-chain reactant than on the tension in a resulting strained ring. According to Dale (1963), a polymethylene chain tends to be straight zig-zag but, when substituted by a methyl group, it does not matter for the neighbouring C—C bond whether the chain itself or the methyl group continues in the trans-position hence the probability of a bent... 

Fig. 23 Entropy effects on intramolecular reactions of polymethylene chains. Plot of 9AS (e.u.) against number of single bonds for (O) nucleophilic substitutions at saturated carbon ( ) electron-exchange reactions (A) quenching of benzophenone phosphorescence. The straight line has intercept +30 e.u. and slope —4.0 e.u. per rotor. The right-hand ordinate reports the purely entropic EM s calculated as exp(0AS /J )...

Si,Si-Dimethyl-Sila-Substituted Derivatives of Polymethylen-bis-Trimethyl-ammonium Compounds with Curare-Like Activity... 

Sherrington and coworkers161 have examined the chlorination of phenol by J-butyl hypochlorite in the presence of cross-linked polystyrenes substituted by pendant polymethylene chains terminated with anionic or cationic head groups, as well as some hydrophilic acrylic polymers, in four solvents water, methanol, 1,2-dichloroethane and xylene. The polymers exerted a significant influence on the chlorination, particularly in polar solvents. However, no changes in the regioselectivity of the chlorination, in comparison to homogeneous systems, was observed. 

The rate of deamination is determined by the chain length and with polymethylene diamines, NH2-(CH2)n-NH2, the maximum rate occurs when n = 4 (putrescine) and n = 5 (cadaverine) and decreases to zero when n = 9 or more. At this chain length, MAO becomes active and can oxidatively deaminate the diamines. It should be noted that although MAO can deaminate both substituted and primary amines, DAO can deaminate only primary amines. 

It unites with both halogens in polymethylene halides (two equivalents of sodium amide are required) to form 1-phenyl cycloalkyl cyanides. The action of substituted alkyl halides on phenyl acetonitrile and its horaologs furnishes valuable intermediates for syntheses. ... 

The synthesis of 2-aminopyrazines (108) unambiguously substituted at the 5-and 6-positions from substituted 2-azabutadienes (107) and ammonia has been described by Lang and Fleury (488). In this way 2-amino-3-cyano(or methoxy-carbonyl)-5-methyl(or ethoxycarbonyl)-6 phenyl(or methyl or 5,6-polymethylene)-pyrazines have been obtained. When the Schiffbase [H2NC(CN)=C(CN)N=C(CN)Ph ... 

In a recent NMR study, Derenne et al.(77) obtained evidence for non hydrolyzable amide structures in refractory fractions of the algae Scenedesmus quadricauda. The solid-state NMR spectra showed a major peak around -260 ppm for amides accompanied by a peak around -195 ppm for substituted pyrroles and a shoulder at -235 ppm assigned to unsubstituted pyrroles of the insoluble residue. The authors suggest, that the amides are protected by association with long polymethylenic chains within a macromolecular network. Knicker and Hatcher offer an alternative explanation,- that protection of amide functional groups as part of proteinaceous material are affected by encapsulation within the macromolecular matrix forming sedimentaryhumic material(7.. ... 

The condensation of /3-aminoacrolein with (61a,c) leads to the corresponding polymethylene-bridged tpys (66b,d) in low yields. The same systems may be prepared more effectively by the condensation of enamines (65a-c) with formaldehyde and subsequent azacyclization of the intermediate 1,5-diketone (Scheme 12).64 A Hantzsch approach to (66b) has also been reported.67 Benzaldehyde, 4-substituted benzaldehydes, and various other aryl aldehydes can be treated with (65a) to afford 4 -aryl derivatives of (66b) in moderate yields.69 A 48% yield of the monomethylene-bridged (66a) has been... 

---