Amine salts, unsaturated

Amides can be titrated direcdy by perchloric acid ia a nonaqueous solvent (60,61) and by potentiometric titration (62), which gives the sum of amide and amine salts. Infrared spectroscopy has been used to characterize fatty acid amides (63). Mass spectroscopy has been able to iadicate the position of the unsaturation ia unsaturated fatty amides (64). Typical specifications of some primary fatty acid amides and properties of bisamides are shown ia Tables 5 and 6. 

The fourth chapter gives a comprehensive review about catalyzed hydroamina-tions of carbon carbon multiple bond systems from the beginning of this century to the state-of-the-art today. As was mentioned above, the direct - and whenever possible stereoselective - addition of amines to unsaturated hydrocarbons is one of the shortest routes to produce (chiral) amines. Provided that a catalyst of sufficient activity and stabihty can be found, this heterofunctionalization reaction could compete with classical substitution chemistry and is of high industrial interest. As the authors J. J. Bmnet and D. Neibecker show in their contribution, almost any transition metal salt has been subjected to this reaction and numerous reaction conditions were tested. However, although considerable progress has been made and enantios-electivites of 95% could be reached, all catalytic systems known to date suffer from low activity (TOP < 500 h ) or/and low stability. The most effective systems are represented by some iridium phosphine or cyclopentadienyl samarium complexes. 

J. A. Dougherty, B. T. Outlaw, and B. A. Oude Alink. Corrosion inhibition by ethoxylated fatty amine salts of maleated unsaturated acids. Patent US 5582792, 1996. 

A further example of the use of a chiral anion in conjunction with a chiral amine was recently reported by Melchiorre and co-workers who described the asymmetric alkylation of indoles with a,P-unsaturated ketones (Scheme 65) [212]. The quinine derived amine salt of phenyl glycine (159) (10-20 mol%) provided the best platform with which to perform these reactions. Addition of a series of indole derivatives to a range of a,P-unsaturated ketones provided access to the adducts with excellent efficiency (56-99% yield 70-96% ee). The substrates adopted within these reactions is particularly noteworthy. For example, use of aryl ketones (R = Ph), significantly widens the scope of substrates accessible to iminium ion activation. Expansion of the scope of nucleophiles to thiols [213] and oximes [214] with similar high levels of selectivity suggests further discoveries will be made. 

The equilibrium for unsaturated amines favors the allyl rather, than the vinyl derivative when the nitrogen atom is in the quaternary amine salt form (equation 4) (66JA3376). It has also been assumed that the N,iV-dimethyl-l,2-dihydropyridinium bromide (16) is more stable than the 1,4-isomer (17) since complete deuterium exchange can be accomplished without isomerization (66JA3376). 

Composition vs. properties. One of the key properties of a soap, key to determining applications, is solubility. As with other surfactants, the solubility of the soap is dependent upon the carbon chain distribution, which is, in turn, determined by the choice of raw material oils. C12-14 gives a more soluble soap with very high foam generation whereas Ci8+ soaps have much reduced solubility. The use of unsaturated acids, such as oleic, gives improved solubility compared to the saturated equivalents and, where high solubility is required, potassium salt or an amine salt may be used instead of sodium salt. 

Hypothesizing that primary amine catalysts, due to their reduced steric requirements, might be suitable for the activation of ketones, we studied various salts of a-amino acid esters. (For pioneering use of primary amine salts in asymmetric iminium catalysis involving aldehyde substrates, see Ishihara and Nakano 2005 Sakakura et al. 2006 for the use of preformed imines of a, 3-unsaturated aldehydes and amino acid esters in diastereoselective Michael additions, see Hashimot et al. 1977.) We have developed a new class of catalytic salts, in which both the cation and the anion are chiral. In particular, valine ester phosphate salt 35 proved to be an active catalyst for the transfer hydrogenation of a variety of a, 3-unsaturated ketones 36 with commercially available Hantzsch ester 11 to give saturated ketones 37 in excellent enantiose-lectivities (Scheme 28 Martin and List 2006). 

Selenolates such as Na2Se, NaSeH, PhSeNa, etc., and tellurolates such as NapTe, NaTeH, PhTeNa, etc., are excellent nucleophiles and can reduce a variety of functional groups by nucleophilic attack or single electron-transfer. On treatment with alkali metal selenolates (or amine salts of HpSe and PhSeH), reduction or reductive selenation of ketones and aldehydes, C=C reduction of a,/l-unsaturated compounds, and reduction of nitrogen compounds such as nitro compounds occur successfully [118, 176]. Compared with these selenolate anions, the corresponding tellurium compounds are highly reactive not only toward the same substrates but also toward halo compounds such as a-bromo ketones and vic-dibromoalkanes [46, 52, 177]. 

The effect of the solid surface on polyurethane formation is specific. The surface does not hinder formation of the pol50irethane itself, although polyaddition on the surface frequently proceeds at a different rate from that in bulk. This is related to the effect of the adsorption ordering the boundary layer on the kinetics of the interaction [29]. The dependence of polyurethane formation on the sohd siuface present is apparently explained by a number of factors. The isocyanate groups are capable of strong interactions with various surfaces (metals, glass), and they can react both with one another and with a great number of other compounds such as water, alcohols, amines, and unsaturated compounds. Many substances (salts of metals, amines, phosphines, and others) catalyze reactions of isocyanate. 

Melchiore et al. reported highly stereoselective aziridinations of linear and cyclic a,p-unsaturated ketones with excellent diastereo- and enantio-selectivity (up to 99% ee). Aziridination was performed using N-protected hydrojylamines and a primary amine salt catalyst, made by combining 9-amino-9-deo)y-ep/-dihydroquinine (9-epz-DHQA) with o-N-Boc-phenylglycine (Scheme 15.8). The first step of the reaction is the nucleophilic addition of Af-protected hydro>ylamine to the iminium intermediate (formed from the enone and amine catalyst salt) followed by an intramolecular cyclisation of the resulting enamine to the aziridine product. 

S.4.4.5. -Substituted Cyclohexenone Derivatives. Inspired with the dien-amine catalysis developed by Jprgensen and co-workers [138], Melchiorre and coworkers [139] found that the chiral primary amine salts 142 could selectively activate the 7-position of ummodified cyclic a,(3-unsaturated ketones through dienamine catalysis (Scheme 5.70). The direct vinylogous Michael addition of p-substituted... 

Amines and amine salts. Primary, secondary and tertiary amines proton-ate to give positive ions corresponding to the amine salt [RiR2R3NH] . This cation can also lose two hydrogen atoms to give an ion that could be confused with that from an unsaturated analogue. The presence of such ions should be taken into account before the determination of unsaturated species is attempted. 

Using a chiral primary amine salt derived from 9-amino-(9-deoxy)-e/>i-hydroquinine, Melchiorre et al. achieved an organocatalytic asymmetric protocol for the highly enantioselective sulfa-Michael addition, which was applicable to a large variety of a,p-unsaturated ketones. The highest enantioselectivities of up to 96% ee combined with high yields were obtained with benzyl mercaptan as a nucleophile, as shown in Scheme 1.69. 

Northrup and MacMillan extended the iminium-mediated Diels-Alder reactions to a,p-unsaturated ketones using a new chiral amine catalyst (Schane 1.43) [66]. They found that cycloaddition of a,P-unsaturated ketones was unsuccessful with the chiral amine salts previously identified as excellent catalysts for enal activation. In contrast, the 2-(5-methylfuryl)-derived imidazolidinone 118 afforded good levels of enantiofacial discrimination while maintaining high reaction efficiency (89% yield, 25 1 endo/exo, 90% ee). 

Aziridinations of a,P-unsaturated ketones triggered by chiral primary amine salts via iminium catalysis were reported soon after (Scheme 1.71) [113]. The reduced steric constraint of primary amines offers the unique possibility of catalyzing processes between sterically demanding parmers, overcoming the inherent difficulty of chiral secondary amine catalysis. The reaction affords valuable N-Cbz- as well as N-Boc-protected aziridines 167 with almost complete diastereocontrol and very high enantioselectivity (up to 99% ee). 

There also exists an acidregioselective condensation of the aldol type, namely the Mannich reaction (B. Reichert, 1959 H. Hellmann, 1960 see also p. 291f.). The condensation of secondary amines with aldehydes yields Immonium salts, which react with ketones to give 3-amino ketones (=Mannich bases). Ketones with two enolizable CHj-groupings may form 1,5-diamino-3-pentanones, but monosubstitution products can always be obtained in high yield. Unsymmetrical ketones react preferentially at the most highly substituted carbon atom. Sterical hindrance can reverse this regioselectivity. Thermal elimination of amines leads to the a,)3-unsaturated ketone. Another efficient pathway to vinyl ketones starts with the addition of terminal alkynes to immonium salts. On mercury(ll) catalyzed hydration the product is converted to the Mannich base (H. Smith, 1964). 

The Perkin reaction, uti1i2ing an aromatic aldehyde, an acid anhydride, and a base such as an acid salt or amine, produces the corresponding a,P-unsaturated acid. 

Aqueous mineral acids react with BF to yield the hydrates of BF or the hydroxyfluoroboric acids, fluoroboric acid, or boric acid. Solution in aqueous alkali gives the soluble salts of the hydroxyfluoroboric acids, fluoroboric acids, or boric acid. Boron trifluoride, slightly soluble in many organic solvents including saturated hydrocarbons (qv), halogenated hydrocarbons, and aromatic compounds, easily polymerizes unsaturated compounds such as butylenes (qv), styrene (qv), or vinyl esters, as well as easily cleaved cycHc molecules such as tetrahydrofuran (see Furan derivatives). Other molecules containing electron-donating atoms such as O, S, N, P, etc, eg, alcohols, acids, amines, phosphines, and ethers, may dissolve BF to produce soluble adducts. 

Glycerol, the simplest trihydric alcohol, forms esters, ethers, haUdes, amines, aldehydes, and such unsaturated compounds as acrolein (qv). As an alcohol, glycerol also has the abiUty to form salts such as sodium glyceroxide (see also Alcohols, polyhydric). 

The presence of ammonia during hydrogenation suppresses formation of secondary amines and inhibits hydrogenation of double bonds in unsaturated nitriles. Eatty amines are used as corrosion inhibitors, flotation agents, quaternary salts for sanitizing agents and textile fabric softeners, and surface-active agents. 

The stereochemical course of reduction of imonium salts by Grignard reagents was found to depend on the structure of the reagent 714). Hydro-boration of enamines and oxidation with hydrogen peroxide led to amino-alcohols (7/5). While aluminum hydrogen dichloride reacted with enamines to yield mostly saturated amines and some olefins on hydrolysis, aluminum hydride gave predominantly the unsaturated products 716). 

The configuration of the amine was retained, except in the case of amino acid derivatives, which racemized at the stage of the pyridinium salt product. Control experiments showed that, while the starting amino acid was configurationally stable under the reaction conditions, the pyridinium salt readily underwent deuterium exchange at the rz-position in D2O. In another early example, optically active amino alcohol 73 and amino acetate 74 provided chiral 1,4-dihydronicotinamide precursors 75 and 76, respectively, upon reaction with Zincke salt 8 (Scheme 8.4.24). The 1,4-dihydro forms of 75 and 76 were used in studies on the asymmetric reduction of rz,>S-unsaturated iminium salts. 

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