Ketones primary amines with

Sodium triacetoxyborohydride is an alternative to NaBH3CN for reductive amination. This reagent can be used with a wide variety of aldehydes or ketones with primary and secondary amines, including aniline derivatives.93 This reagent has been used successfully to alkylate amino acid esters.94... 

Schiff base org chem RR C=NR" Any of a class of derivatives of the condensation of aldehydes or ketones with primary amines colorless crystals, weakly basic hydrolyzed by water and strong acids to form carbonyl compounds and amines used as chemical intermediates and perfume bases, in dyes and rubber accelerators, and in liquid crystals for electronics, shif, bas ... 

C. EtkyUnimine Ketones and Related Syntheses Closely related to the Gabriel synthesis is the reaction of /9-dihaloketones or cc-hslo-a -unsaturated ketones with primary amines... 

Imines. Imines are usually prepared by acid-catalyzed condensation of aldehydes or ketones with primary amines with azeotropic removal of water. This method gives poor yields with low-boiling imines.2 A new method involves dehydrocyanation of a-cyanoamines with DCC and Dabco as catalyst (equation I).3... 

N-substituted amines are produced by reaction of ketones with primary amines, followed by reduction. 

The reaction of homopropargylic ketones with primary amines is an excellent method for the synthesis of highly substituted pyrroles. As shown for one example in Scheme 12.16, the yields often are better with the silver catalyst.33... 

Imines are formed by condensation of aldehydes or ketones with primary amines, but they form with more difficulty than enamines.84,85 A special case of enamine preparation was described with 20-oxo-steroids.86 Treatment of these ketones with a primary amine gives a 20-ketimine, which is acetylated with acetic anhydride, with migration of the double bond and formation of 20-(A-acetylalkylamino)-J17(20)-pregnene (14) reduction of 14 with lithium aluminum hydride affords the enamine. 

Imines are formed from aldehydes or ketones with primary amines... 

Simple double aza-Michael reaction of divinyl ketones with primary amines was utilized to generate TV-substituted 3-phenyl-4-piperidones in good yields <07EJO4376>. In a somewhat similar mode, the diastereoselective synthesis of cyclic (3-amino esters by an Sn2 substitution-cyclization of an iodo-a,(3-unsaturated ester with (.Sj-u-mcthy 1 benzylamine was described <07OBC3614>. A combination intramolecular Michael-type addition followed by retro-Michael elimination was exploited in the generation of a phosphoryl dihydropyridone intermediate in the synthesis of /m .v-2,6-disubstitutcd 1,2,5,6-tetrahydropyridines <07JOC2046>. 

Schiff base. A class of compounds derived by chemical reaction (condensation) of aldehydes or ketones with primary amines. The general formula is RR X=NR". 

Schiff base. An imine, derived by chemical condensation of aldehydes or ketones with primary amines very weakly basic and hydrolyzed by water to form carbonyl compounds and amines. 

Reaction of Aldehydes and Ketones with Primary Amines... 

Like acetal formation, the reaction of aldehydes and ketones with primary amines— compounds of the type RNH2 and ArNH2—is a two-stage process. Its first stage is nucleophilic addition of the amine to the carbonyl group to give a carbinolamine. The second stage is the dehydration of the carbinolamine to yield the isolated product of the reaction, an A-alkyl or A-aryl-substituted imine. 

Dake has reported a gold(I)-catalyzed protocol for the condensation/hydroamina-tion of y-alkynyl ketones with primary amines to form pyrrole derivatives [31]. For... 

Ketimines Imines of the type R2C=NHR formed by the reaction of ketones with primary amines. The two groups designated R in the general formula may be the same or different... 

Scheme 4-287. Iron-catalyzed [4C+1N] cyclization of 3-alkynyl-substituted ketones with primary amines.

A class of nitrogen containing compounds that was omitted from the section just dis cussed includes mines and their derivatives Immes are formed by the reaction of aide hydes and ketones with ammonia Immes can be reduced to primary amines by catalytic hydrogenation... 

The treatment of ketoximes with lithium aluminum hydride is usually a facile method for the conversion of ketones into primary amines, although in certain cases secondary amine side products are also obtained. Application of this reaction to steroidal ketoximes, by using lithium aluminum deuteride and anhydrous ether as solvent, leads to epimeric mixtures of monodeuterated primary amines the ratio of the epimers depends on the position of the oxime function. An illustrative example is the preparation of the 3(x-dj- and 3j5-di-aminoandrostane epimers (113 and 114, R = H) in isotopic purities equal to that of the reagent. 

The use of primary amines instead of ammonia affords l,2-dialkyl-/l -pyrrolines or l,2-dialkyl-/l -piperideines. Amino ketones with a primary amino group are intermediates in the reduction of y-nitropropylalkyl ketones (14,15) or S-nitrobutylalkyl ketones (16-18) by catalytic hydrogenation over Raney nickel or with zinc and hydrochloric acid (Scheme 1). 

Formation of C—Nu The second mode of nucleophilic addition, which often occurs with amine nucleophiles, involves elimination of oxygen and formation of a C=Nu bond. For example, aldehydes and ketones react with primary amines, RNH2, to form imines, R2C=NR. These reactions proceed through exactly the same kind of tetrahedral intermediate as that formed during hydride reduction and Grignard reaction, but the initially formed alkoxide ion is not isolated. Instead, it is protonated and then loses water to form an imine, as shown in Figure 3. 

Mechanism of imine formation by reaction of an aldehyde or ketone with a primary amine. 

Reaction of an aldehyde or ketone with a secondary amine, R2NH, rather than a primary amine yields an enamine. The process is identical to imine formation up to the iminium ion stage, but at this point there is no proton on nitrogen that can be lost to form a neutral imine product. Instead, a proton is lost from the neighboring carbon (the a carbon), yielding an enamine (Figure 19.10). 

An aldehyde or ketone reacts with a primary amine, RNH.2, to yield an imine, in which the carbonyl oxygen atom has been replaced by the =N-R group of the amine. Reaction of the same aldehyde or ketone with a secondary amine, R2NH, yields an enamine, in which the oxygen atom has been replaced by the -NR2 group of the amine and the double bond has moved to a position between the former carbonyl carbon and the neighboring carbon. 

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