528586-23-4Relevant academic research and scientific papers
Highly practical BINOL-derived acid-base combined salt catalysts for the asymmetric direct mannich-type reaction
Hatano, Manabu,Ishihara, Kazuaki
body text, 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.
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).
Effects of methyl substituents on the activity and enantioselectivity of homobenzotetramisole-based catalysts in the kinetic resolution of alcohols
Zhang, Yuhua,Birman, Vladimir B.
scheme or table, p. 2525 - 2529 (2009/12/28)
Substitution of the tetrahydropyrimidine ring in the enantioselective acyl transfer catalyst homobenzotetramisole (HBTM) 6 with methyl groups exerts a dramatic influence on its performance in the kinetic resolution of secondary alcohols. The syn-3-methyl analogue of HBTM (9a) has proved to be superior to the parent compound in terms of catalytic activity, enantioselectivity, and synthetic accessibility.
METHOD FOR THE PRODUCTION OF CHIRAL AMINOCARBONYL COMPOUNDS
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Page/Page column 5, (2009/12/04)
Disclosed is a method for producing aminocarbonyl compounds of the general formula (I) wherein R1 and R2 can be identical or different and represents hydrogen, alkyl, alkenyl, alkynyl, or aryl,X represents hydrogen, alkyl, alkenyl, alkynyl, aryl, or OR3, R3 representing hydrogen, alkyl, alkenyl, alkynyl, or aryl. According to said method, an aldehyde of the general formula (II) [in-line-formulae]R1CO??(II)[/in-line-formulae] wherein R1 has the meaning indicated above, is reacted with an imine of the general formula (III) wherein R2 and X have the meaning indicated above, in the presence of a catalyst. Aminocarbonyles are obtained by means of catalyzed Mannich reactions with aldehydes. For example, if α-unbranched aldehydes are reacted with previously formed N-Boc imines in the presence of (S)-proline as a catalyst, the desired β-amino aldehydes are obtained at excellent yields, diastereoselectivities and enantioselectivities.
Enantioselective mannich reactions with the practical proline mimetic N-(p-dodecylphenylsulfonyl)-2-pyrrolidinecarboxamide
Yang, Hua,Carter, Rich G.
supporting information; experimental part, p. 2246 - 2249 (2009/08/07)
A highly enantioselective and diastereoselective protocol for performing Mannich reactions has been developed by using a p-dodecylphenylsulfonamide-based proline catalyst. This catalyst facilitates the use of common, nonpolar solvents and increased concen
1-Amido-1-phenyl-3-piperidinylbutanes - CCR5 antagonists for the treatment of HIV: Part 2
Barber, Christopher G.,Blakemore, David C.,Chiva, Jean-Yves,Eastwood, Rachel L.,Middleton, Donald S.,Paradowski, Kerry A.
scheme or table, p. 1499 - 1503 (2009/12/07)
Optimisation of a series of 4-piperidinyltriazoles led to the identification of compound 28a which showed good whole cell antiviral activity, excellent selectivity over the hERG ion channel and complete oral absorption.
CHEMICAL COMPOUNDS
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Page/Page column 28, (2009/09/05)
The present invention provides compounds of formula (I) wherein R1, R2, R3, R4, Het and m are as defined in the description. The compounds of the present invention are modulators, especially antagonists, of the
Asymmetric aza-Michael reactions of α,β-unsaturated ketones with bifunctional organic catalysts
Lu, Xiaojie,Deng, Li
supporting information; experimental part, p. 7710 - 7713 (2009/04/11)
Synergy makes it possible: Bifunctional cinchona alkaloids are found to promote the first highly enantioselective organocatalytic aza-Michael reactions with α,β-unsaturated ketones. In addition to utilizing practical catalysts, readily accessible substrates, and commercially available reagents, this reaction affords a synthetically valuable scope that is complimentary to existing methods catalyzed by chiral metal complexes.
Evidence for an enol mechanism in a highly enantioselective Mannich-type reaction catalyzed by primary amine-thiourea
Yalalov, Denis A.,Tsogoeva, Svetlana B.,Shubina, Tatyana E.,Martynova, Irina M.,Clark, Timothy
body text, p. 6624 - 6628 (2009/03/12)
(Chemical Equation Presented) A tale of two mechanisms - enol versus enamine: Chiral primary amine-thiourea 1 catalyzes highly enantioselective Mannich-type addition of unmodified ketones to N-benzoylhydrazones (see scheme). The reaction does not require
Proline-catalyzed Mannich reaction of aldehydes with N-Boc-imines
Yang, Jung Woon,Stadler, Michael,List, Benjamin
, p. 609 - 611 (2008/02/01)
(Chemical Equation Presented) A curious cat.: The proline-catalyzed Mannich reaction between aldehydes and N-Boc-imines (Boc = tert-butoxycarbonyl) gives crystalline β-amino aldehydes with exceptionally high diastereoselectivities and enantioselectivities
