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Metal-free catalysis Mannich reactions

The use of diazocarbonyls with acid catalysis under metal-free conditions has been reviewed (45 references), covering 1,3-dipolar cycloadditions, rearrangements, three-membered ring formation and Mannich-type and aldol reactions. ... [Pg.56]

The actual catalyst in phosphoric acid-catalyzed Mannich-type reaction of imines with 1,3-dicarbonyl compounds is certainly phosphoric acid itself [74], but metal contaminants, such as alkali or alkaline-earth metals, have interesting effects on the reactivity and stereoselectivity. HCl-washed, metal-free chiral phosphoric acid 149a and chiral calcium phosphate 149b are able to catalyze the Mannich-type reactions. The absolute stereoselectivity of the phosphoric acid catalysis is opposite that of the calcium phosphate catalysis (Scheme 28.16) [75]. [Pg.817]

See other pages where Metal-free catalysis Mannich reactions is mentioned: [Pg.61]    [Pg.712]    [Pg.712]    [Pg.142]    [Pg.353]    [Pg.411]    [Pg.793]    [Pg.793]   
See also in sourсe #XX -- [ Pg.131 , Pg.132 , Pg.133 , Pg.134 , Pg.135 , Pg.136 , Pg.137 , Pg.138 , Pg.139 , Pg.140 , Pg.141 ]



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Catalysis metal-free

Free metal

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