Amides, preparation from

The conjugate addition of Grignard reagents to 2-cyclohexenone was promoted by catalytic amounts (2-4 mol %) of alkylcopper(I) complexes of the lithium amide prepared from N- (R)-1 -phenylethyl]-2-[(/ )-l-phenylethyliminojcycloheptatrienamine, Li[CuR(CHIRAMT)]52,11. However, 3-substituted cyclohexanones were obtained in very low ee (4-14%). 

Amides prepared from carboxylic acids and ammonia using CDI. Yields refer to reaction of the azolides with ammonia. 

The following amides prepared from 4-(3-nitro-l-pyrazolyl)butanoic acid, CDI, and primary amines represent partial structures of the histamine H2-receptor antagonists roxatidine, cimetidine, ranitidine, and famotidine [37]... 

Amides prepared from carboxylic acids and primary amines using azolides obtained from acid chloride/imidazolea) or ketene/imidazole systems.b)... 

Amides prepared from secondary amines and acylchloride/imidazole,[391 carboxylic acid/oxalyldiimidazole,[41 ] carboxylic acid/sulfinyldiimidazole[61 ] or isolated imidazo-... 

Amides prepared from carboxylic acids and amines containing other reactive groups (OH, C02H) by using CDI. 

Amides prepared from OH- or NH-containing carboxylic acids and amines by using CDI. 

The following are further examples of amides prepared from carboxylic acids/CDI and primary amines activated by magnesium salts (additional examples are reported in ref. [90]) ... 

Amides prepared from both enantiomers of 10,10-dimethyl-4-aza-3-thiatricyclor5.2.1.01,5ldecane 3,3-dioxide (bornane-10,2-sultam) can be used in diastereoselective alkylation reactions to give high chemical yields and high diastereomeric ratios of monoalkylation products5,6,10,16-19. 

The bulk of the researches on the amidoAn compounds have been on U and, to a lesser extent, Th. The only examples in the open literature of transuranic amides are on the homoleptic Np and Pu bis(trimethylsilyl)amides, prepared from the appropriate [Anl3(thf)4] and 3Na N(SiMe3)2 in thf this was also the preferred procedure for [U N(SiMe3)2 3]. Pu N(SiMe3)2 3 was cited as a catalyst precursor its molecular structure has been reported recently. 

Oxazolines.1 Hydroxy amides, prepared from p-hydroxy amines and acid chlorides, are converted into 2-oxazolines with the Mitsunobu reagent at 0 — 25° (equation I). 

Analogous to the use of chiral enoates (see previous section), a, -unsaturated carboxylic amides, prepared from chiral amines, may be utilized in asymmetric 1,4-additions. When Grignard reagents are added to unsaturated amides (21), derived from (-)-ephedrine (20),25 highly optically active fi-sub-stituted alkanoic acids (22 R and R = alkyl or phenyl) are obtained in a variety of cases, after hydrolysis of the initially formed adducts (Scheme 7). This method was used for the synthesis of the antibiotic (-) malyngolide and its stereoisomers.26 Recrystallization of the intermediate (saturated) amide was necess-... 

Pictet-Spengler cyclization of L-tryptophan with formaldehyde afforded the monochiral carboxylic acids 20a,b, whereas cyclization with acetaldehyde yielded the diastereomeric carboxylic acids 21a,b (23). Acids 20a,b with a hydrogen at C-1 are enantiomers, but acids 21a,b are diaste-reomers the cis isomer 21a was the major reaction product when the cyclization of L-tryptophan with acetaldehyde was carried out in the presence of sulfuric acid. Direct removal of the carboxy group in these acids is difficult, but it can be accomplished in several steps dehydration of the amides prepared from the acids with phosphorus oxychloride affords nitriles, and the nitrile group can be removed by reduction with sodium borohydride in pyridine-ethanol (31). 

The magnesium amide prepared from ethyl magnesium bromide and aniline, with 2-carbomethoxy-lO-methylphenothiazine (164), gives the anilide 165. 

Sodium amide (prepared from 8.6 g of sodium metal) in a 1-L Schlenk flask is suspended in THF (300mL). With rapid stirring, MejC,H (ref. 9) (42.6g,... 

Chapter 10 Fatty Acid Amides Preparation from Common Household Oils... 

In addition to the acetate aldol problem, stereoselective aldol additions of substituted enolates to yield 1,2-anti- or f/treo-selective adducts has remained as a persistent gap in asymmetric aldol methodology. A number of innovative solutions have been documented recently that provide ready access to such products. The different successful approaches to anri-selective propionate aldol adducts stem from the design of novel auxiliaries coupled to the study of metal and base effects on the reaction stereochemistry. The newest class of auxiliaries are derived from A-arylsulfonyl amides prepared from readily available optically active vicinal amino alcohols, such as cw-l-aminoindan-2-ol and norephedrine. 

Cinnamic esters or amides prepared from optically active alcohols (menthol, aryl ethanol) or amines are hydrogenated to products in only low optical yields (less than 40%). Camphor sultam is a much better rr-face discriminator and the hydrogenation of the trisubstituted olefinic bond of sultam-imides over Pd-on-carbon affords, after saponification, j3-substituted carboxylic acids in high e.e. (>95%) ... 

Note thal only Mn-amides prepared from aromatic amines, ArRNH or A NH, give quantitative yields of enolization products. A procedure using only a catalytic amount of aromatic amine has also been described.6... 

Cleavage of the S-N bond734 of sulfonamides, yielding sulfonic acids, has preparative interest when purification of the sulfonic acid by way of the chloride is difficult and is better achieved by recrystallization of the amide prepared from the chloride. The amide is hydrolysed in a hydrochloric acid medium.735 HC1... 

The Swem oxidation of A-Fmoc-protected -amino alcohols 8 (Scheme 4) and the reduction of Weinreb amides prepared from Fmoc-a-amino acids with LiAlH4 at — 78°C were compared [83]. Both approaches afforded comparable synthetic yields, typically between 70 and 90% of the... 

Identification of Acyl Chlorides.—The reactions of acyl chlorides which are most helpful in their identification, are those which take place when they are treated with water, with alcohol, and with ammonia. Reaction takes place readily with these substances. When an acyl chloride is mixed with a small quantity of water or alcohol, hydrogen chloride is evolved. In the case of certain chlorides gentle heat is necessary to bring about reaction. The physical properties of the chloride together with those of the acid, ester, or amide prepared from it serve to complete its identification. 

The amides prepared from sulphonic acids crystallize well from hot water, and possess well defined melting points. They are, as a consequence, of service in effecting the identification of sulphonic acids. 

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