Amides alkylations

Alkylphenol polyethyleneglyool ethers Fatty aold alkanol amides Alkyl amides... 

Thickeners. These are used to kicrease viscosity of shampoos to achieve certain consistency characteristics ki the product, from a thickened Hquid to gels and pastes. Among the most important materials used for this purpose are the alkanolamides. The chain length of the amide alkyl group and its solubiHty ki the shampoo system are important aspects to be considered ki thek use for effects on viscosity. In general, as the chain length increases the viscosity response improves. The viscosity increase also is related to the water solubiHty of the amide the more water-soluble forms provide a lower viscosity response than the less soluble amides. 

Hydrazinium salts, N2H5 X, are acids in anhydrous hydrazine, metallic hydrazides, N2H, are bases. Neutralization in this solvent system involves the hydrazinium and hydrazide ions and is the reverse of equation 7. Metal hydrazides, formally analogous to the metal amides, are prepared from anhydrous hydrazine and the metals as well as from metal amides, alkyls, or hydrides. (The term hydrazide is also used for organic compounds where the carboxyUc acid OH is substituted with a N2H2.) Sodium hydrazide [13598-47-5] is made from sodium or, more safely, from sodium amide (14) ... 

Amines or amides Alkyl amines (iindecyloctyl and diamyl methyl amine) polyamides (acyl derivatives of piperazine) Boiler foam sewage foam fermentation dye baths... 

The OPLS parameters (charges and Lennard-Jones terms) were obtained primarily via Monte Carlo simulations with particular emphasis on reproducing the experimental densities and heats of vaporization of liquids. Those simulations were performed iteratively as part of the parametrization, so better agreement with experiment is obtained than in previous studies where the simulations were usually carried out after the parametrization. Once the OPLS parametrization was completed, further simulations were also performed in order to test the new set of parameters in the calculation of other thermodynamic and structural properties of the system, besides its density and its heat of vaporization. Parameters have now been generated, among others, for water, alkanes, alkenes, alcohols, amides, alkyl chlorides, amines, carboxylic esters and acids, various sulfur and nitrogen compounds, and nitriles. A protein force field has been established as well. 

The reactivity of lithium enolates has been explored in a theoretical study of the isomers of C2H30Li, such as the lithium enolate, the acyl lithium, and the a-lithio enol. Imides containing a chiral 2-oxazolidine have been employed for enantioselective protonation of prochiral enolates.A degree of kinetic control of the product E/Z-enolate ratio has been reported for the lithiation of 3,3-diphenylpropiomesitylene, using lithium amides/alkyls. " °... 

A wide range of a,P-unsaturated acceptors work well under standard reaction conditions with pre-catalyst 75c (Table 7). Acceptors include a,P-unsaturated esters, amides, alkyl ketones, and phosphine oxides, many of which provide the products in greater than 90% ee [68, 69], a,P-Unsaturated phenyl ketones, nitriles, and thioesters also work, albeit with lower enantioselectivity. The scope has been extended to include a variety of vinyl phosphonate precursors providing good chemical yields and moderate to high enantioselectivity (entries 9 and 10). 

When a 1,2,5-thiadiazole-l-oxide contains a 3-methoxy-4-hydroxy array (28), the system reacts as an amide alkylation occurs on nitrogen (29) allowing selective amination at position C-3 (30) (Scheme 6) <85TL6155>. 

In contrast to the many examples dealing with esters (see Section 1.1.1.3.2.), there are few examples in the literature of alkylations of amide enolates where the steric course is governed by the configuration of chiral units on the carbon side of the starting amide, i.e., substrate control by C-chirality. It is likely, however, that amide alkylations of this type will emerge as a very useful procedure since amide enolates are easy to prepare and usually, in contrast to some esters, provide very high ratios of syn- to a / -enolate. 

Both enantiomers of 2-methylamino-l-phenylpropanol (ephedrine, 1), which are commercially available and relatively inexpensive, have been used as auxiliaries in many syntheses of chiral compounds. Ephedrine can be used for amide alkylations both directly1-3, or as derived heterocyclic compounds (see Sections 1.1.1.3.3.4.2.1. and 1.1.1.3.3.4.2.2.). Acyclic derivatives of ephedrine are discussed in this section. For example, either enantiomer of ephedrine gives A-acylephedrines 2 in good yield without epimerization if treated with an anhydride at 65 °C for 10 minutes2. 

The C2-symmetrical chiral amine tran.v-(2/ ,6y )-2,6-bis(benzyloxymethyl)piperidine (1), prepared15 from commercially available (S)-2-(benzyloxymethyl)oxirane, has been used in diastereoselective amide alkylations. Thus, the chiral amine of 76% ee is acylated [anhydride or mixed trimethylacetic acid anhydride, 1.2 equivalents of triethylamine and 0.05 equivalents of 4-(dimethylamino)pyridine] and the resulting amide 2 treated with 2.1 equivalents of lithium diisopropylamide at —78 CC to give the enolate. This is then alkylated to give high diastereo-meric ratios (>94 6) of alkylation products 3 in 60-93% yield16. 

The second major location of variations in the structure of LSD has been in the nature of the alkyl groups on the amide nitrogen atom. Some of these are Sandoz syntheses, some are from other research groups, and a few of them are found in nature. Some of these have been studied in man, and some have not. A few of the original clutch of Sandoz compounds have both 1-substituents and amide alkyl (R) group variations ... 

In the case of the series derived from homocysteine 32, the critical transformation proved to be formation of the eight-membered ring. This was successful only if the aniline nitrogen was present in its nonalkylated form. Thus the synthetic efforts were restricted to the amide alkylation... 

Enantioselectire alkylation of amides. Two laboratories12 have used (S)-prolinol as the chiral auxiliary for a synthesis of chiral amides. Alkylation of the enolate of the amide 1 (prepared with LDA or f-butyllithium) proceeds with pronounced... 

Houghten and co-workers[145] introduced a method for combinatorial synthesis of a per-alkylated peptide library using nonspecific N-alkylation. The peptides were synthesized by SMPS methodology 146 in combination with repetitive amide N-alkylation on the solid support after each coupling step. Peptides were synthesized on MBHA-PSty resin using Fmoc chemistry. After Fmoc deprotection the a-amino group was protected by Trt to prevent N -alkylation and to allow only amide alkylation. The on-resin amide alkylation was achieved by amide proton abstraction using LiOtBu in THF followed by nonfunctionalized alkyl and aryl halides in DMSO. 

The enantiomerically pure oxazolidinone derivative 7 (Scheme 4),14,20 was converted into the metathesis precursor 6 by a sequence of carbamate hydrolysis, amide alkylation and protection of the secondary alcohol as the TBDMS ether in a 95% overall yield. Subsequent [Ru-1] catalysed ROM-RCM converted 6 into the desired dihydropyrrole 5. 

Stepwise Selective Amine and Amide Alkylation (Fig. 14) 44 A first alkylation step is performed by suspending (78) in a 2 M solution of a suitable alkyl halide in DMF at 50° for 24-48 h. After thorough washing with DMF (3x), CH2C12 (3x), and THF (3x) intermediate (79) (usually formed with >85% purity) is subjected to the final alkylation. The reaction flask is sealed with a fresh rubber septum and flushed with nitrogen followed by cooling to 0°. In a separate flame-dried 25-ml round-bottom flask 12 equiv. (with respect to 79) of 5-phenylmethyl-2-oxazolidinone is added. To the reaction flask freshly distilled THF is added (the appropriate volume to provide a 0.2 M solution of the 5-phenylmethyl-2-oxazolidi-none). The resulting clear solution is then cooled to —78° and 1.6 M n-butyl... 

The nature of alkyl halide and the environment of the phosphorus atom make a substantial contribution to the direction of the reaction. Thus, cyclic phosphites [108], like trialkyl phosphites [110], react with preservation of the coordination of the P(III) phosphorus atom (126-132 ppm). If the alkoxyl group is substituted by amide, alkyl, or aryl, the nucleophilicity of the phosphorus atom in the corresponding amidophosphite (phosphonite) increases in comparison with the trialkyl phosphite. This probably promotes attack by 1 -haloalkyl-2-pyrrolidone at the phosphorus atom and not the oxygen, and this was confirmed experimentally. As a result of the investigated reactions amidophosphonates or ethyl phenyl phosphinates llOa-c were isolated compounds with P(III) were not detected in these cases. 

Structurally characterized heterobimetallic Ln/Al complexes bearing donor-functionalized dianionic diamido ligands of the types [NNN]2" and [NON]2- were obtained from [amide]- [alkyl] (Scheme 52) or [aluminate] [amide] interchange reactions (Scheme 53). 

Scheme 52 Generation of terminal tetramethylaliuninate complexes via selective [amide]- [alkyl] interchange [222]...

Finally, a samarium aluminate tetramer featuring /J-dikeliminalo ligands was obtained in low yield (20%) by J. Arnold et al. (Scheme 54) [224], Once again this example corroborates the feasibility of selective [amide] [alkyl] transformations in N-ligand-based postlanthanidocene chemistry, previously observed for octaethylporphyrin yttrium complexes by C.J. Schaverien [225, 226],... 

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