Carbonyl compounds polycondensation

Polyethers are obtained from three different classes of monomers, namely, carbonyl compounds, cyclic ethers, and phenols. They are manufactured by a variety of polymerization processes, such as polymerization (polyacetal), ring-opening polymerization (polyethylene oxide, polyprophylene oxide, and epoxy resins), oxidative coupling (Polyphenylene oxide), and polycondensation (polysulfone). 

Aldol Reaction (Condensation) [24] Traditionally, it is the acid- or base-catalyzed condensation of one carbonyl compound with the enolate/enol of another, which may or may not be the same, to generate a P-hydroxy carbonyl compound— an aldol. The method is composed of self-condensation, polycondensation, generation of regioisomeric enols/enolates, and dehydration of the aldol followed by Michael addition, q.v. The development of methods for the preparation and use of preformed enolates or enol derivatives that dictate specific caibon-caibon bond formation have revolutionized the coupling of carbonyl compounds (Fig. 6.6) ... 

Dilithium tetrachlorocuprate is recommended as an additive for cross coupling of Grignard compounds with tosylates even allylic and benzylic acetates give good yields . a-Methylene-ketones, -carboxylic acids and -lactones have been prepared via sulfides and sulfoxides. A convenient and general synthesis of acetylene derivatives from boranes via the reaction of iodine with lithium 1-alkynyltriorganoborates has been published ar-Nitrostyrenes can be easily obtained by a Wittig synthesis with formaldehyde in an aqueous medium . A new synthesis of unsym. ketones by reaction of dialkyldiloroboranes with lithium aldimines has recently been published . Metallo aldimines have also served for the synthesis of a variety of other compound classes such as a-hydroxyketones, a-keto acids, nitriles, and for the asym. synthesis of a-amino acids . Polycondensations of malononitriles with benzylic chlorides have been carried out quantitatively under mild conditions in dimethyl sulfoxide with triethylamine as acid acceptor . Carbonyl compounds can react with dibromoacetonitrile to yield a-bromo esters with additional carbon atom . ... 

Phenol resins are polycondensation products of phenols with carbonyl compounds, mostly formaldehyde 31-133) Condensation under acid conditions with a deficiency of formaldehyde yields soluble, thermoplastic phenol resins. Es ntially the... 

Wittig polycondensation route has been widely used for the preparation of alternating copolymers in which carbonyl compounds such as aldehyde and ketone are... 

The presence of quinones in coal and oxidized coals and the products of the reaction of the latter with bisdiazonium compounds have also received some attention. An absorption band at 1640 cm-, observed in the spectra of model compounds obtained from the polycondensation of phenanthrene, pyrene, and chrysene with formaldehyde and subsequent pyrolysis and nitric acid oxidation, was also assigned to nonchelated quinoid carbonyl groups. This band was absent from the spectra of coal, oxidized coals and their products after reaction with bisdiazonium compounds after pyrolysis and oxidation with nitric acid. 

Carbonylation was applied in oligomerizations and polycondensations as well, even though most of the previous work focused on monocarbonylation reactions. Chaudhari and colleagues reported a palladium-catalyzed carbonylation-polycon-densation reaction of aromatic diiodides and aminohydroxy compounds [117]. With their methodology, alternating polyesteramides were prepared in chlorobenzene with l,8-diaza-bicyclo[5.4.0]undec-7-ene (DBU) as a base under 3 bar of carbon monoxide at 120 °C (Scheme 2.8). 

POLYAMIDE. Separations are based on formation of hydrogen bonds between the functional groups of the sample (phenols, amino acid derivatives, heterocyclic nitrogen compounds, carboxylic and sulfonic acids) and the carbonyl oxygen of the amide group, as well as a general reversed-phase partition mechanism (water is the weakest solvent). Available as two polycondensation products, polyundecanamide (PA 11) and polycaprolactam (PA 11). 

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