Diols amination

Reactants of the A—A (or B—B) type are not likely to undergo direct cyclization instead of linear polymerization. A groups do not react with each other and B groups do not react with each other under the conditions of step polymerization. Thus there is usually no possibility of anhydride formation from reaction of the carboxyl groups of a diacid reactant under the reaction conditions of a polyesterification. Similarly, cyclization does not occur between hydroxyl groups of a diol, amine groups of a diamine, isocyanate groups of a diisocyanate, and so on. 

Because of its very short lifetime, no spectroscopic observations of 1 were possible even at low temperature. However, we provided evidence for the transient formation of 1 by trapping reactions with alcohols, diols, amines,methyl iodTtle, epoxides, dienes, ketones. Some examples are as follows. 

Furandicarboxylic acid Fructose, glucose (via HMF intermediate) Diol, amine, levulinic acid, succinic acid, 2,5 -fu rand icarbaldehyde, 2,5-dihydroxymethyl-furan, tetrahydrofuran, polyethylene, terephthalate analogues. Werpy and Petersen 2004... 

More recently, dithionylium salts (3.45A) have been explored for reactions with diols, amines and even azide [225], in the presence of fluoride sources, and an electrophilic brominating agent 5,5-dimethylhydantoin (DBH) to effect desulphurisation. High yields are obtained under very mild conditions (Figure 3.45). 

A self-assembled POM [ZnWZn2(ZnW9O34)2] prepared in situ in water by mixing zinc nitrate, sodium tungstates, and nitric acid was active for the oxidation of alcohols, diols, amines, and pyridines with [94,95]. The catalyst was... 

But in order to utilise these reactions, a few conditions must be met. A selective enzyme is crucial and the organometallic catalyst must facilitate a fast racemisation of the substrate. Last, but not least, the catalyst should not influence the enzyme in terms of selectivity and reactivity. In the ideal case, the enzyme transforms one enantiomer of the substrate, giving rise to the corresponding product, which is not susceptible to metal-catalysed racemisation. Three major types of enzyme-metal combinations—lipase-ruthenium, sub-tilisin-ruthenium and lipase combined with a metal other than ruthenium—have been developed primarily as the catalysts for the DKRs of various secondary alcohols but also for diols, amines and esters. Meanwhile, the lipase-ruthenium combination has been the most used method up to the present time. 

Maleinated rubbers have been successfully treated with metal oxides, diols, amines, and isocyanates, to give rubber products with improved flex... 

This chapter is divided into five sections according to the type of enzyme and substrate involved in the DKR. The first and principal section addresses the usefulness of hydrolases (particularly lipases) for the DKR of alcohols, diols, amines, and esters. In the following sections, DKRs with other enzymes such as haloalcohol dehalogenase. 

The reaction conditions applied are usually heating the amine with a slight excess of aldehyde and a considerable.excess of 2d-30hydrochloric acid at 100 °C for a few hours, but much milder ( physiological ) conditions can be used with good success. Diols, olefinic double bonds, enol ethers, and glycosidic bonds survive a Pictet-Spengler reaction very well, since phenol and indole systems are much more reactive than any of these acid sensitive functional groups (W.M. Whaley, 1951 J.E.D. Barton, 1965 A.R. Battersby, 1969). 

Triflates of phenols are carbonylated to form aromatic esters by using PhjP[328]. The reaction is 500 times faster if dppp is used[329]. This reaction is a good preparative method for benzoates from phenols and naphthoates (473) from naphthols. Carbonylation of the bis-triflate of axially chiral 1,1 -binaphthyl-2,2 -diol (474) using dppp was claimed to give the monocarboxy-late 475(330]. However, the optically pure dicarboxylate 476 is obtained under similar conditions[331]. The use of 4.4 equiv. of a hindered amine (ethyldiisopropylamine) is crucial for the dicarbonylation. The use of more or less than 4.4 equiv. of the amine gives the monoester 475. 

CycHc carbonates are made by treating 1,2-diols with dialkyl carbonates using an alkyl ammonium and tertiary amine catalyst. The combination of propylene glycol and dimethyl carbonate has been reported to result in a 98% yield of propylene carbonate (21). 

Polycarbonates are prepared commercially by two processes Schotten-Baumaim reaction of phosgene (qv) and an aromatic diol in an amine-cataly2ed interfacial condensation reaction or via base-cataly2ed transesterification of a bisphenol with a monomeric carbonate. Important products are also based on polycarbonate in blends with other materials, copolymers, branched resins, flame-retardant compositions, foams (qv), and other materials (see Flame retardants). Polycarbonate is produced globally by several companies. Total manufacture is over 1 million tons aimuaHy. Polycarbonate is also the object of academic research studies, owing to its widespread utiUty and unusual properties. Interest in polycarbonates has steadily increased since 1984. Over 4500 pubflcations and over 9000 patents have appeared on polycarbonate. Japan has issued 5654 polycarbonate patents since 1984 Europe, 1348 United States, 777 Germany, 623 France, 30 and other countries, 231. 

Trickle bed reaction of diol (12) using amine solvents (41) has been found effective for producing PDCHA, and heavy hydrocarbon codistiUation may be used to enhance diamine purification from contaminant monoamines (42). Continuous flow amination of the cycloaUphatic diol in a Hquid ammonia mixed feed gives >90% yields of cycloaUphatic diamine over reduced Co /Ni/Cu catalyst on phosphoric acid-treated alumina at 220°C with to yield a system pressure of 30 MPa (4350 psi) (43). 

The 1,4-isomer has been similarly generated from terephthalonitdle [623-26-7] (56) using a mixed Pd/Ru catalyst and ammonia plus solvent at 125 °C and 10 MPa (100 atm). It is also potentially derived (57) from terephthaUc acid [100-21-0] by amination of 1,4-cyclohexanedimethanol (30) [105-08-8], Endocyclization, however, competes favorably and results in formation of the secondary amine (31) 3-a2abicyclo[3.2.2]nonane [283-24-9] upon diol reaction with ammonia over dehydration and dehydrogenation catalysts (58) ... 

The palladium-promoted conversion of 1,3-dienes to pyrroles proceeds via 4-acetoxy-2-alkenylpalladium complexes (Scheme 50g) (81CC59), and a similar pathway may be involved in the palladium mediated reaction of but-2-ene-l,4-diol with primary amines to give A-substituted pyrroles (74CC931). 

The method should not be used for the first member of a homologous series or for temperatures much above the normal boiling point (T 0.75). Errors for both hydrocarbons and nonhydrocarbons average 15 percent for a wide variety of compounds. Higher errors are noted for amines, diols, ethers, and fluorides. Table 2-398 gives AN and AB contributions for most common groups. Space prohibits examples for... 

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