Ketones amines with

Carmack20 has suggested that thiirenes are intermediates in the classic Willgerodt and Kindler reactions of aldehydes or ketones with amines and sulfur (Scheme 3). 

Most enamines, unfortunately, are sensitive to hydrolysis. The parent enamine, iV,iV-dimethylvinylamine, has in fact been prepared [3], but appears to be unstable. Enamines of cyclic ketones and many aldehydes can readily be isolated, however [4-7]. The instability of enamines might at first appear to diminish the utility of enamines as nucleophiles, but actually this property can be viewed as an added benefit enamines can be readily and rapidly generated catalytically by using a suitable amine and a carbonyl compound. The condensation of aldehydes or ketones with amines initially affords an imine or iminium ion, which then rapidly loses a proton to afford the corresponding enamine (Scheme 1). 

In the reaction of /h/f-difluoro ketones with amines, a,/I-unsaturated / -amino ketones are formed, either by inline formation and imine enaminc tautomerization or via elimination of hydrogen fluoride and subsequent substitution of the other fluorine.22 Geminal sp2-bonded difluoridcs arc converted into ketenimines.12-49,89,90... 

The following two synthetic techniques are applied for obtaining complexes of aliphatic, aromatic, and heterocyclic imines in the limits of the discussed variant of the template synthesis interaction of coordinated mono- and diamines with mono- and dicarbonyl derivatives (method A) and reactions of complexes of o-hydroxyalde-hydes (ketones) with amines and diamines (method B). The simplest transformation of this type is represented by the reaction (3.176) [53,54] ... 

A. Preparation op Enamines by Condensation of Aldehydes and Ketones with Amines... 

Bismuth(m) nitrate catalyzes Michael addition of a,/Yunsaturated ketones with amines, thiols, and carbamates, although the promoting role of Bi(N03)3 is not fully understood (Equation (91)).100 The Biginelli cyclocondensation of a mixture of (3-keto esters, aldehydes, and urea is mediated by BiCl3, affording 3,4-dihydropyrimidin-2(lH)-ones (Equation (92)).149 Bi(OCOCF3)3 is an efficient catalyst for the regio- and chemoselective synthesis of /3-enaminones in water.150... 

Unlike the photochemistry of ketones with amine donors, simple thio-ethers often do not lead to the reduction of ketones [183] due to the slower rate of proton transfer from the thioether cation radicals to the ketyl radical anions than back electron transfer. PET reactions of several other sulphur compounds with ketones have been summerised in Mariano s review [11],... 

Reductive amination of carbonyl compounds. This reagent effects reductive ami-nation of aldehydes or ketones with amines (equation 1). Yields tend to be only moderate with anilines, but are high with aliphatic amines. 

The formation of Schiff bases by the reaction of ketones with amines is more difficult. Acetophenone and other aryl alkyl ketones which are slow to react under the usual conditions will combine with aromatic amines at 160-180° in the presence of a zinc chloride-aniline salt. In another procedure, 2-acetylthiophene and aniline are condensed in boiling toluene with the aid of a water separator. ... 

The enantioselective reduction of a C=N double bond is an interesting alternative for the production of chiral amines by hydrogenation of enamides. Required imines or oximes can be prepared by reaction of ketones with amines or hydroxylamines. However, to date, trials to reduce these substrates with ethyl-DuPHOS catalysts gave no satisfying results. Therefore, transformation of ketones or a-keto acids into acylhydrazones and subsequent enantioselective hydrogenation has proven advantageous (eq 12, Table 5). ... 

Ketimines and enamines. Ketimines and enamines are prepared conveniently by the reaction of ketones with amines in the presence of molecular sieves (Linde 5A was used). Yields are 40-88%. ... 

The reagent is an effective catalyst for the condensation of tillylic alcohols with 2-methyl-1,4-naphthohydroquinone (in dioxane at 50°) and for the condensation of ketones with amines to form azomethines. ... 

Reductive amination of aldehydes or ketones with amines and formic acid (Miquonac) or NaBH4 (see Borch), see also Eschneiler-Clarke (see 1st edition) or H2-Ni... 

Reactions of aldehydes and ketones with amines (Section 18.6). 

Huber and Schwoererdescribe e.s.r. experiments which show the existence of quintet states (S = 2) after u.v. irradiation at 4.5 K in perdeuteriated / -toluene-substituted diacetylene. Nine e.s.r. transitions per quintet were detected and were attributed to bicarbenes of short oligomers. E.s.r. has also been applied to the study of photochemical reactions of fluoro-substituted ketones with amines, tetraphenylborates, and organometals." ... 

Reductive amination Treatment of aldehydes or ketones with amines and the borane-pyridine complex in methanol in the presence of 4 A molecular sieves leads to secondary amines. 

Sodium cyanide-promoted eondensation of aldehyde, or ketone, with amine to afford a-amino nitrile, whieh may be hydrolyzed to a-amino aeid. 

The study aids for this chapter include key terms and concepts (which are hyperlinked to the Glossary from the bold, blue terms in the WileyPLUS version of the book at wileyplus.com), Mechanism Summaries regarding reactions of aldehydes and ketones with amines as well as with other nucleophiles, and a Synthetic Connections scheme regarding transformations of aldehydes and ketones. 

Titanium alkoxides (ethoxide, isopropoxide and tert-butoxide) were also used recently for catalyzing the production of substituted indoles,with acceptable yields from cyclization of o-bromobenzylketones, 89, and primary alkyl amines or anilines, 90 (reaction 7.15) [65]. Melkonyan et al. proposed that the reaction sequence includes a titanium alkoxides catalysis reaction of ketones with amines to give imines and following intra-molec-ular cyclization into indoles, 91, using copper catalysis. Without titanium catalyst and amines the product of cyclization was almost 92. 

The complexes of chiral amino-alcohols of type (13) with borane are reported to reduce aryl alkyl ketones to alcohols in optical yields up to 60% [for propiophenone reduction with (13 R = CHMe2)]/ whereas the asymmetric reduction of phenyl alkyl ketones with amine-boranes formed from chiral amines (such as 1-phenylethylamine or various L-a-amino-esters) has been found to give low optical yields of alcohols, i.e. up to 23%. ... 

Reactions of aldehydes and ketones with amines and amine derivatives (Section 17.10) a. Reaction with a primary amine forms an imine. The mechanism is shown on page 811. 

Lu L, Chen G, Ma S (2006) Ring-opening cyclization of alkylidenecyclopropyl ketones with amines an efficient synthesis of 2,3,4-trisubstituted pyrroles. Org Lett 8 835-838... 

Reaction of labeled aryl halomethyl ketones with amines furnishes j8-amino[ C] ketones. If e.p. amines are employed, subsequent reduction of the keto group with achiral reducing agents produces diastereomeric mixtures of )8-amino alcohols. The individual diastereomers can usually be separated by achiral chromatographic methods, or if these fail chiral HPLC procedures or salt formation with a chiral acid (e.g. dibenzoyl-L-tartaric acid) may prove successful. This pathway was followed for the preparation of [ C]dilevalol (12), an antihypertensive agent (Figure 6.8). Within this synthetic sequence the reaction of the a-bromomethyl ketone 8 with e.p. (7 )-Wbenzyl-(l-methyl-3-phenyl)propylamine (2)... 

Hasegawa, E., Ishiyama, K., Horaguchi, T., and Shimizu, T., Exploratory study on photoinduced single electron transfer reactions of a,P-epoxy ketones with amines, /. Org. Chem., 56,1631, 1991. Hasegawa, E., Ishiyama, K., Horaguchi, T., and Shimizu, T., Free radical trapping of a-keto radicals derived from a,P-epoxy ketones via photoinduced single electron transfer process. Tetrahedron... 

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