Mannich reaction synthetic utility

S. K. Bur, S. F. Martin, Vinylogous Mannich Reactions Selectivity and Synthetic Utility, Tetrahedron 2001, 57, 3221-3242. 

The amino group of Mannich bases 247 can be replaced by various X residues by reaction with nucleophilic HX reactants to give the X-alkylated products 248 (Fig. 92) This reaction, which also may be formally regarded as an X-alkylation by the R—CH2— moiety of the Mannich base, is of considerable synthetic utility.-- -- - " ... 

Vinylogous Mannich Reactions. Selectivity and Synthetic Utility," Bur, S.K. Martin. S.F. Tetrahedron, 2001, 57, 3221. 

The synthetic utility of benzotriazole derivatives as >N—C< >N=C< synthons has been explored by Katritzky and his coworkers. The Mannich reaction of benzotriazole with primary aliphatic amines RNH2 and formaldehyde in an aqueous medium results in the formation of one or more of three types of product BtCH2NHR, (BtCH2)2NR and (BtCH2NR)2CH2 [Bt = benzotriazol-l-yl (93)]. Benzotriazole and aliphatic or aromatic aldehydes yield compounds 94. The parent compound 1-hydroxymethylbenzotriazole reacts with aromatic amines to give secondary amines 95, primary aliphatic amines give the tetiary amines 96 and aqueous ammonium acetate at room temperature yields 97. The 1-benzotriazoles 98 are obtained from benzotriazole, aldehydes and aromatic amines ... 

The importance of the Mannich reaction stems from the synthetic utility of the resulting aminoketones. Thermal decomposition of the amines or the derived... 

The importance of the Mannich reaction stems from the synthetic utility of the resulting aminoketones. Thermal decomposition of the amines or the derived quaternary salts leads to a-methylene ketones. The decomposition of the quaternary salts is particularly facile, and they can be used as in situ sources of many a,j3-unsaturated carbonyl compounds. These are useful synthetic intermediates, for... 

Chen et al. have described a convenient and efficient synthetic protocol for preparation of a-aminophosphinic acid derivatives (583) in high yields and high enantiostereoselectivity, utilizing SnCU as the promoter and O-pivaloylated D-galactosylamine in (582) moiety as a chiral auxiliary by means of a Mannich-type reaction (Scheme 143). 

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