1234571-62-0Relevant articles and documents
Which is the actual catalyst: Chiral phosphoric acid or chiral calcium phosphate?
Hatano, Manabu,Moriyama, Katsuhiko,Maki, Toshikatsu,Ishihara, Kazuaki
supporting information; experimental part, p. 3823 - 3826 (2010/08/22)
(Figure Presented) Both catalysts work: A highly enantioselective direct Mannich-type reaction of NBoc-protected aldimines with 1,3-dicarbonyl compounds has been developed with the use of a chiral phosphoric acid in the presence or absence of Ca . The absolute stereoselectivity of the phosphoric acid catalysis was found to be opposite to that of the calcium phosphate catalysis (see scheme; Boc = tert-butoxycarbonyl).
Highly practical BINOL-derived acid-base combined salt catalysts for the asymmetric direct mannich-type reaction
Hatano, Manabu,Ishihara, Kazuaki
experimental part, p. 3785 - 3801 (2011/02/16)
The catalytic asymmetric direct Mannich-type reaction between aldimines and 1,3-dicarbonyl compounds is one of the most important carbon-carbon bond-forming reactions in organic chemistry. The resulting Mannich adducts can be efficiently transformed into pharmaceutically useful, optically active -amino ketones, -amino esters, -lactams, etc. In the course of our study of chiral acid-base combined salt catalysts for asymmetric reactions, we developed a series of simple, practical, chiral BINOL-derived salt catalysts, such as chiral pyridinium 1,1-binaphthyl-2,2-disulfonates 1, chiral lithium(I) binaphtholate 2, chiral magnesium(II) binaphtholate (3), chiral calcium(II) phosphate 4, and chiral phosphoric acid 5, which were particularly effective for direct Mannich-type reactions. 1 Introduction 2 1,1-Binaphthyl-2,2-disulfonic Acid (BINSA)-Pyridinium Salts 3 Lithium(I) Binaphtholate Salts 4 Magnesium(II) Binaphtholate Salts 5 Calcium(II) Phosphate Salts and Chiral Phosphoric Acids 6 Conclusions. Georg Thieme Verlag Stuttgart · New York.
