P-aminocarbonyl compounds

Razumov, A.L, Sokolov, M.P, Liorber, B.G., Zykova, T.V, Salakhutdinov, R.A., and Uimancheeva, G.V., Reactivity and structure of phosphorylated carbonyl compounds. Part 14. Study of the reaction of phosphorylated acetaldehydes with P-aminocarbonyl compounds, Zh. Obshch. Khim., 47, 2717, 1977 J. Gen. Chem. USSR (Engl. Transl.), 47, 2474, 1977. 

It is clear that these alkylimidazohum ILs containing nonprotic anions present a very low acidity. However, [MIM][Bp4] has been used successfully for esterification of a variety of carboxylic acids with common alcohols. Good yields and high selectivity for the esters are described. The esters are immiscible with the ILs while water is soluble in them, so that liquid esters can be separated by decanting [18]. Another example is the three-component (aldehyde, amine, ketone) Mannich reaction that provides p-aminocarbonyl compounds used in pharmaceutical and biological areas of chemistry. [MIMjlCFjCOj] IL acts as both a solvent and a catalyst for the reaction, which simplifies the reaction procedure [19]. 

A general bismuth-triflate-catalyzed direct-type Mannich reaction of cyclohexanone with imines derived from various benzaldehydes and anilines was reported. P-Aminocarbonyl compounds are obtained efficiently in the presence of 5 mol%... 

The asymmetric Mannich reaction is a powerful tool for preparation of chiral p-aminocarbonyl compounds (for a review of asymmetric Mannich-type reactions for synthesis of a,p-diamino acids, see [83, 84] for reviews of direct Mannich-type reactions [85-89]). Up to now, several chiral catalysts have been developed, and high stereoselectivities have been achieved. In this Mannich reaction, chiral alkaline-earth metal complexes have also been successfully employed. 

In our discussion, many calixarens have been mentioned in number of chemical reactions as catalyst, however out of these, quaternary ammonium-terminated calixarenes calix[4]arene 4 and calix[6]arene 2 catalysts were used in one-pot Mannich reaction of benzaldehyde, acetophenone and aniline in aqueous media to produce p-aminocarbonyl compounds (see Fig. 27.7) [19]. These calix[n]arene catalysts emphasized not only the high catalytic activity but also have an outstanding reusability with high yield, at low loading amoxmt. Advantages of that were, short reaction times, high yields, and easy work-up that make them great candidate for Mannich-type reactions (see Table 27.5). 

Two carbonyl compounds (1 and 3) can combine to form [l-hydroxycarbonyl compounds (4) in the aldol reaction, discovered by Kane in 1838 [8j. The addition of carbonyl compounds (1) to the imine (5) to form P-aminocarbonyl compounds (6), called the Mannich reaction, was discovered by Marie and Tollens in 1903 (Scheme 28.1) [9]. These synthetically and historically important break-... 

The Mannich reaction consists on the condensation of a CH-activated compound with a primary or a secondary amine and a non-enolizable aldehyde or ketone to afford p-aminocarbonyl derivatives known as Mannich bases (Scheme 20). This sequence is of great use for the constmction of heterocyclic targets, as illustrated for example by the Robinson-Schopf synthesis of tropinone in 1937 or by the preparation of some azabicyclo[3.3.1]nonanones or pyranocoumarine derivatives (Fig. 1) [100]. In the following, representative recent examples of the formation of five- to seven-membered ring heterocycles will be presented. 

The last topic in this chapter is the Michael addition of heteroatoms such as nitrogen and sulfur that affords P-aminocarbonyl and [Lthiocarbonyl compounds. 

Mannich reaction The reaction of a ketone with formaldehyde in the presence of an amine or ammonia under acidic conditions to give the 3-aminocarbonyl adduct, which is referred to as a Mannich base. After methylation and heating with silver oxide, the a,(3-unsaturated P-carbonyl compound may be formed. 

The classic direct Mannich reaction discovered in 1912 [192a] is an aminoalkylation of carbonylic compounds involving ammonia (or a primary or secondary amine derivative), a non-enolizable aldehyde (usually formaldehyde) or a ketone, and an enolizable carbonyl compound, leading to P-aminocarbonyl derivatives [192b-e]. The indirect version of the Mannich reaction is the corresponding two-component reaction of a preformed iminium salt [193] and an enolizable carbonyl compound. 

Another [IJrotaxane R25 via covalent-bond formation based on a crownlike macrocycle has been reported previ-onsly, as shown in Figure 15 P The eqnimolar reaction of 4 with 5 gave bicyclic compound 3 (mixtnre of two isomers). Then 3, without separation of isomers, was used in aminol-ysis with 9-(3-(aminopropyl) aminocarbonyl)-anthracene 2. Treatment of mixed isomers of 3 with 2 in DMF at room temperature gave birth to [IJrotaxane R25 (yield 20%) and a reference compound Ref-R25 (yield 45%). R25 had a three-dimensionally small cavity constructed by the ring and the chain connected with the macrocycle, which could catch only the lithium ion with a drastic enhancement of fluorescence intensity of the R25 solution. 

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