Epoxide reaction with amines

Over the last decade, a considerable number of reactions has been studied (11,35) (i) olefins oxidation (38,39), hydroboration, and halogenation (40) (ii) amines silylation (41,42), amidation (43), and imine formation (44) (iii) hydroxyl groups reaction with anhydrides (45), isocyanates (46), epichloro-hydrin and chlorosilanes (47) (iv) carboxylic acids formation of acid chlorides (48), mixed anhydrides (49) and activated esters (50) (v) carboxylic esters reduction and hydrolysis (51) (vi) aldehydes imine formation (52) (vii) epoxides reactions with amines (55), glycols (54) and carboxyl-terminated polymers (55). A list of all the major classes of reactions on SAMs plus relevant examples are discussed comprehensively elsewhere (//). The following sections will provide a more detailed look at reactions with some of the common functional SAMs, i.e hydroxyl and carboxyl terminated SAMs. 

Catalysis by acids, which is only rarely effective for aliphatic amines but better suited to the less basic aromatic amines [334], can promote nucleophilic attack at the most strongly polarized C-0 bond of the epoxide (Scheme 4.75) [333, 334, 339]. Vinyl epoxides react with amines in the presence of Pd(0) under mild conditions to yield allylamines [340], If such reactions are performed in the presence of an enantiomerically pure ligand, racemic vinyl epoxides can be converted into enantiomerically enriched products of nucleophilic ring opening (last example, Scheme 4.75). 

Sodium cyanide in DMF at 120 °C has been used for the decarboxylation of 1-substituted-4-oxoquinoline-3-carboxylic acids <94TL(35)8303>. Quinoline Reissert adducts have been epoxidized at the 3,4-bond. Its reaction with amine nucleophiles gave regiospecifically substituted 1,2,3,4-tetrahydroquinolines <95H(41)897>. Successive Claissen rearrangements of 2-(8-quinolinoxymethyl)-3-(8-quinolinoxy)-l-propene gave a product which shows excellent ability to extract heavy metal ions <95TL(36)5567>. An Eschenmoser approach has been used in a facile synthesis of monofunctional and difunctional A -substituted-4-alkylidenequinolines (54) (Scheme 39) <95S(St)56>. 

The partially epoxidized compound was shown to have an average of two epoxy groups per cube. Both polyepoxides readily polymerized in the presence of Lewis acid catalysts or in reaction with amines. This suggested their potential as coupling agents in the synthesis of novel inorganic-organic hybrids. 

Oxirane ring opening of epoxidized HOSME with amines and particularly with butylamine is more difficult than with the former reactants. The difficult point is that the opening of the oxirane group competes with the transamidation reaction. Figure 5 describes the competition between these reactions. We actually observed that transamidation always joins amination. 

A thermoset polymer containing one or more epoxide groups and curable by reaction with amines, alcohols, phenols, carboxylic acids, acid anhydrides, and mercap-tans. It has been primarily used as a matrix resin in composites and adhesives. 

The susceptibility of the amide bond of azetidinones to nucleophiles has been utilized for the synthesis of many heterocycles. Pyrrolidinones (103) may be obtained by treatment of the epoxide (102) with amines, whereas a paper by Crockett et al. draws attention to the long known but little used preparation of imides [e.g. (104)] by heating di-acids or anhydrides with urea. It is claimed that the reaction is easily managed on a large scale and that yields are often better than those of other procedures. 

Vinyl-functional alkylene carbonates can also be prepared from the corresponding epoxides in a manner similar to the commercial manufacture of ethylene and PCs via CO2 insertion. The most notable examples of this technology are the syntheses of 4-vinyl-1,3-dioxolan-2-one (vinyl ethylene carbonate, VEC) (5, Scheme 24) from 3,4-epoxy-1-butene or 4-phenyl-5-vinyl-l,3-dioxolan-2-one (6, Scheme 24) from analogous aromatic derivative l-phenyl-2-vinyl oxirane. Although the homopolymerization of both vinyl monomers produced polymers in relatively low yield, copolymerizations effectively provided cyclic carbonate-containing copolymers. It was found that VEC can be copolymerized with readily available vinyl monomers, such as styrene, alkyl acrylates and methacrylates, and vinyl esters.With the exception of styrene, the authors found that VEC will undergo free-radical solution or emulsion copolymerization to produce polymeric species with a pendant five-membered alkylene carbonate functionality that can be further cross-linked by reaction with amines. Polymerizations of 4-phenyl-5-vinyl-l,3-dioxolan-2-one also provided cyclic carbonate-containing copolymers. 

An early example of chiral alcohol-based hydrogen bonding catalysts is the work by Braddock and coworkers in which they used paracydophanediols (PHANOLs) as dual H-bond donors [65, 66]. Significant rate enhancements were obtained in the Diels-Alder reactions of dienes with a,P-unsaturated aldehydes and ketones and in the epoxide-opening reactions with amines. However, little or no asymmetric induction was obtained when a chiral PHANOL catalyst was used. 

The zwitterion (6) can react with protic solvents to produce a variety of products. Reaction with water yields a transient hydroperoxy alcohol (10) that can dehydrate to a carboxyUc acid or spHt out H2O2 to form a carbonyl compound (aldehyde or ketone, R2CO). In alcohoHc media, the product is an isolable hydroperoxy ether (11) that can be hydrolyzed or reduced (with (CH O) or (CH2)2S) to a carbonyl compound. Reductive amination of (11) over Raney nickel produces amides and amines (64). Reaction of the zwitterion with a carboxyUc acid to form a hydroperoxy ester (12) is commercially important because it can be oxidized to other acids, RCOOH and R COOH. Reaction of zwitterion with HCN produces a-hydroxy nitriles that can be hydrolyzed to a-hydroxy carboxyUc acids. Carboxylates are obtained with H2O2/OH (65). The zwitterion can be reduced during the course of the reaction by tetracyanoethylene to produce its epoxide (66). 

AH of the amine hydrogens are replaced when MDA or PMDA reacts with epoxides to form amine based polyols. These polyols can be used in reactions with isocyanates to form urethanes or with additional epoxide to form cross-linked thermo set resins. 

General Reaction Chemistry of Sulfonic Acids. Sulfonic acids may be used to produce sulfonic acid esters, which are derived from epoxides, olefins, alkynes, aHenes, and ketenes, as shown in Figure 1 (10). Sulfonic acids may be converted to sulfonamides via reaction with an amine in the presence of phosphoms oxychloride [10025-87-3] POCl (H)- Because sulfonic acids are generally not converted directiy to sulfonamides, the reaction most likely involves a sulfonyl chloride intermediate. Phosphoms pentachlotide [10026-13-8] and phosphoms pentabromide [7789-69-7] can be used to convert sulfonic acids to the corresponding sulfonyl haUdes (12,13). The conversion may also be accompHshed by continuous electrolysis of thiols or disulfides in the presence of aqueous HCl [7647-01-0] (14) or by direct sulfonation with chlorosulfuric acid. Sulfonyl fluorides are typically prepared by direct sulfonation with fluorosulfutic acid [7789-21-17, or by reaction of the sulfonic acid or sulfonate with fluorosulfutic acid. Halogenation of sulfonic acids, which avoids production of a sulfonyl haUde, can be achieved under oxidative halogenation conditions (15). 

The most important Lewis bases are tertiary amines or polyamines converted into tertiary amines upon reaction with epoxide groups. 

Compounds are prepared by a fairly standard sequence which consists of condensation of an appropriate phenol with epichlorohydrin in the presence of base. Attack of phenoxide can proceed by means of displacement of chlorine to give epoxide (45) directly. Alternatively, opening of the epoxide leads to anion 44 this last, then, displaces halogen on the adjacent carbon to lead to the same epoxide. Reaction of the epoxide with the appropriate amine then completes the synthesis. 

An alternative strategy, avoiding the danger of over-reaction with diax.omethane, is to make the diazonium salt, by diazotisation of a hydroxy amine (14), available from the original ketone (12) via epoxide (13),... 

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