37088-67-8Relevant academic research and scientific papers
Multicomponent Catalytic Enantioselective Synthesis of Isoxazolidin-5-Ones
Annibaletto, Julien,Brière, Jean-Fran?ois,Levacher, Vincent,Martzel, Thomas,Oudeyer, Sylvain
supporting information, p. 4447 - 4451 (2021/08/09)
We report herein a strategy to afford a multicomponent catalytic enantioselective synthesis of β-substituted isoxazolidin-5-ones via a KMC process promoted by a suited cupreine used as bifunctional organocatalyst. The hydroxamic acid component, with a ste
Chiral Lewis Base-Catalyzed, Enantioselective Reduction of Unprotected β-Enamino Esters with Trichlorosilane
Ye, Jianheng,Wang, Chao,Chen, Lin,Wu, Xinjun,Zhou, Li,Sun, Jian
, p. 1042 - 1047 (2016/04/19)
Catalytic asymmetric reduction of N-unsubstituted β-enamino esters represents a major challenge for asymmetric catalysis. In this paper, the first organocatalytic system that could be used for the asymmetric hydrosilylation of N-unsubstituted β-enamino esters has been developed. Using N-tert-butylsulfinyl-L-proline-derived amides and L-pipecolinic acid-derived formamides as catalyst, a broad range of β-aryl- and β-alkyl-substituted free β-amino esters could be prepared with high yields and enantioselectivities. The practicality was illustrated by the gram-scale asymmetric synthesis of ethyl (R)-3-amino-3-phenylpropanoate and isopropyl (S)-3-amino-4-(2,3,5-trifluorophenyl)butanoate. The resulting product can be smoothly transformed to the FDA approved medicines dapoxetine and sitagliptin in a short synthetic route.
Stereoselective synthesis of activated 2-arylazetidines via imino-aldol reaction
Ghorai, Manas K.,Das, Subhomoy,Das, Kalpataru,Kumar, Amit
, p. 9042 - 9049 (2015/09/01)
A simple and efficient synthetic route to substituted N-sulfinyl and N-sulfonyl azetidines is described involving imino-aldol reaction of ester enolates with racemic and non-racemic aldimines for obtaining β-amino esters as a key step. These β-amino ester
Studies on N-activation for the lipase-catalyzed enantioselective preparation of β-amino esters from 4-phenylazetidin-2-one
Sundell, Riku,Kanerva, Liisa T.
, p. 1500 - 1506 (2015/03/04)
The effect of N-substitution was examined for the enantio-selective lipase-catalyzed ring-opening reaction of racemic 4-phenylazetidin-2-one with methanol in dry organic solvents. Marked differences in the reactivity of various N-protected 4-phenylazetidin-2-ones were observed. Preparativescale reactions with Candida antarctica lipase B (Novozym 435 preparation) yielded N-acylated methyl (R)-3-amino-3- phenylpropanoates with enantiomeric excess (ee) values >99% in up to a 49% isolated yield, whereas Thermomyces lanuginosus lipase (Lipozyme TM IM) gave enantiomerically enriched methyl (S)-3-acetamido-3-phenylpropanoate. Candida antarctica lipase A catalyzed the cleavage of the N-chloroacetyl protective group, whereas all of the other examined lipases underwent the ring-opening reaction.
METHOD FOR PRODUCING beta-AMINOCARBONYL COMPOUND
-
Paragraph 0024, (2013/04/10)
An optically active β-aminocarbonyl compound is obtained by a Mannich reaction between an aldimine in which: nitrogen is protected and a malonic acid diester, in the presence of optically active BINOL and dialkyl magnesium (in which two alkyl groups are the same or different) in an amount 1 to 2 molar times the amount of the BINOL.
Direct catalytic asymmetric addition of acetonitrile to N-thiophosphinoylimines
Kawato, Yuji,Kumagai, Naoya,Shibasaki, Masakatsu
, p. 11227 - 11229 (2013/11/19)
Direct catalytic addition of acetonitrile pronucleophiles to thiophosphinoylimines is described. Soft Lewis acid-hard Bronsted base cooperative catalysis is crucial to promote this elusive carbon-carbon bond-forming reaction in an enantioselective fashion
Enantioselective organocatalytic α-alkylation of ketones by S N1-type reaction of alcohols
Trifonidou, Maria,Kokotos, Christoforos G.
supporting information; experimental part, p. 1563 - 1568 (2012/04/23)
The enantioselective α-alkylation reaction of cyclic ketones is described. Our catalyst, based on a "privileged" pyrrolidine ring bearing a chiral thioxotetrahydropyrimidinone ring, is a highly reactive catalyst for cyclic ketones. When this catalyst was coupled with in situ generated carbocations derived from alcohols, the corresponding α-alkylated adducts were obtained in moderate to quantitative yields and low to high enantioselectivities (up to 80% ee). The catalyst loading can be efficiently reduced to 10%, which is the lowest value reported in the literature for such an organocatalytic transformation.
Triclorosilane-mediated stereoselective synthesis of β-amino esters and their conversion to highly enantiomerically enriched β-lactams
Guizzetti, Stefania,Benaglia, Maurizio,Bonsignore, Martina,Raimondi, Laura
supporting information; experimental part, p. 739 - 743 (2011/04/22)
A highly stereoselective trichlorosilane-mediated reduction of N-benzyl enamines was developed; the combination of a low cost, easy to make metal-free catalyst and an inexpensive chiral auxiliary allowed to perform the reaction on substrates with different structural features often with total control of the stereoselectivity. By easy deprotection through hydrogenolysis followed by conversion of β-aminoester to 2-azetidinones, the synthesis of enantiomerically pure β-lactams (>98% e.e.) was successfully accomplished.
Photodesulfinylation of optically active N-sulfinyl amines
Davis, Franklin A.,Ramachandar, Tokala,Zhang, Yanfeng,Chai, Jing,Qiu, Hui,Deng, Jianghe,Velvadapu, Venkata
experimental part, p. 4042 - 4044 (2010/08/07)
Photolysis of enantiopure N-sulfinyl amines (sulfinamides) in Et2O-MeOH gives amines in good yield without racemization.
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.
