55441-99-1Relevant articles and documents
A Chiral, Dendralenic C-H Acid
H?fler, Denis,List, Benjamin
supporting information, p. 38 - 39 (2021/12/29)
We report the synthesis of a chiral dendralenic C H acid, which contains three unsubstituted binaphthyl moieties. This motif and an achiral variant can be made from their corresponding bis(sulfone) precursors in one step. Despite the presence of the enantiopure binaphthyl backbone, the newly designed chiral C H acid showed only poor enantioselectivity in a Mukaiyama aldol reaction. First attempts toward the synthesis of 3,3'-hexasubstituted binaphthyl-based dendralenic acids are also reported.
PROCESS FOR PRODUCTION OF DISULFONIC ACID COMPOUND, ASYMMETRIC MANNICH CATALYST, PROCESS FOR PRODUCTION OF -AMINOCARBONYL DERIVATIVE, AND NOVEL DISULFONATE SALT
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Page/Page column 7, (2010/08/07)
Hexamethylphosphoramide (HMPA) was added to a reaction vessel containing (R)-1,1'-binaphthyl-2,2'-dithiol and potassium hydroxide. The vessel was purged with oxygen and stirred at 80°C for 5 days under 7 atmospheres of oxygen. After being cooled to room temperature, the reaction product was purified to yield potassium (R)-1,1'-binaphthyl-2,2'-disulfonate. The (R)-1,1'-binaphthyl-2,2'-disulfonic acid obtained from the disulfonate and 2,6-diphenylpyridine were stirred in acetonitrile, and then the solvent was evaporated under reduced pressure. Subsequently, magnesium sulfate and distilled CH2Cl2 were added to the reaction product, and the mixture was stirred at room temperature for 30 minutes. The resulting solution was cooled to 0°C. Benzaldehyde imine whose nitrogen is protected with Cbz and subsequently acetyl acetone were dropped into the solution over a period of 1 hour. The resulting mixture was further stirred at 0°C for 30 minutes. A corresponding β-aminocarbonyl derivative was thus produced with an yield of 91% and an enantiomeric excess of 90% ee.
Highly practical BINOL-derived acid-base combined salt catalysts for the asymmetric direct mannich-type reaction
Hatano, Manabu,Ishihara, Kazuaki
scheme or table, 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.
