119880-58-9Relevant academic research and scientific papers
Metal-Free Deoxygenation of Chiral Nitroalkanes: An Easy Entry to α-Substituted Enantiomerically Enriched Nitriles
Pirola, Margherita,Faverio, Chiara,Orlandi, Manuel,Benaglia, Maurizio
, p. 10247 - 10250 (2021/06/18)
A metal-free, mild and chemodivergent transformation involving nitroalkanes has been developed. Under optimized reaction conditions, in the presence of trichlorosilane and a tertiary amine, aliphatic nitroalkanes were selectively converted into amines or nitriles. Furthermore, when chiral β-substituted nitro compounds were reacted, the stereochemical integrity of the stereocenter was maintained and α-functionalized nitriles were obtained with no loss of enantiomeric excess. The methodology was successfully applied to the synthesis of chiral β-cyano esters, α-aryl alkylnitriles, and TBS-protected cyanohydrins, including direct precursors of four active pharmaceutical ingredients (ibuprofen, tembamide, aegeline and denopamine).
Water-Enabled Catalytic Asymmetric Michael Reactions of Unreactive Nitroalkenes: One-Pot Synthesis of Chiral GABA-Analogs with All-Carbon Quaternary Stereogenic Centers
Sim, Jae Hun,Song, Choong Eui
, p. 1835 - 1839 (2017/02/05)
Water enables new catalytic reactions for otherwise unreactive substrate systems. Under the “on water” reaction conditions, extremely unreactive β,β-disubstituted nitroalkenes smoothly underwent enantioselective Michael addition reactions with dithiomalonates using a chiral squaramide catalyst, affording both enantiomers of highly enantioenriched Michael adducts with all-carbon-substituted quaternary centers. The developed “on water” protocol was successfully applied for the scalable one-pot syntheses of chiral GABA analogs with all-carbon quaternary stereogenic centers at the β-position, which might show highly interesting pharmaceutical properties.
Substrate Scope Evaluation of the Enantioselective Reduction of β-Alkyl-β-arylnitroalkenes by Old Yellow Enzymes 1-3 for Organic Synthesis Applications
Bertolotti, Mattia,Brenna, Elisabetta,Crotti, Michele,Gatti, Francesco G.,Monti, Daniela,Parmeggiani, Fabio,Santangelo, Sara
, p. 577 - 583 (2016/02/23)
The substrate scope of the old yellow enzyme catalyzed reduction of β-alkyl-β-arylnitroalkenes is investigated. Compounds bearing either alkyl chains of increasing length at the carbon atom in position β to the nitro group or different substituents on the aromatic ring are prepared and submitted to bioreduction, to define the synthetic potential of this enantioselective reaction in the preparation of chiral fine chemicals. The versatility of the resulting nitroalkanes as chiral building blocks is shown by reducing the nitro group into a primary amine and by converting it into a carboxylic acid moiety by Meyer reaction. An "explosion" of chiral products can be observed by combining the highly enantioselective ene-reductase-mediated reduction of nitroalkenes with the chemical versatility of the nitro group.
Iridium-Catalyzed Enantioselective Hydrogenation of β,β-Disubstituted Nitroalkenes
Liu, Man,Kong, Duanyang,Li, Meina,Zi, Guofu,Hou, Guohua
, p. 3875 - 3879 (2016/01/25)
A highly efficient, iridium-catalyzed, enantioselective hydrogenation of β,β-disubstituted nitroalkenes has been developed. Using a complex consisting of iridium and (S,S)-f-spiroPhos as the catalyst, a variety of β,β-disubstituted nitroalkenes were successfully hydrogenated to the corresponding chiral nitroalkanes with excellent enantioselectivities (up to 98% ee) and high turnover numbers (TON=1000).
Highly substituted enantioenriched cyclopentane derivatives by palladium-catalyzed [3 + 2] trimethylenemethane cycloadditions with disubstituted nitroalkenes
Trost, Barry M.,Bringley, Dustin A.,O'Keefe, B. Michael
supporting information, p. 5630 - 5633 (2013/12/04)
β,β-Disubstituted nitroalkenes readily undergo palladium-catalyzed [3 + 2] cycloaddition with trimethylenemethane to generate nitrocyclopentanes in excellent yield and enantioselectivity. The reaction provides access to heavily substituted cyclopentanes c
Readily available hydrogen bond catalysts for the asymmetric transfer hydrogenation of nitroolefins
Schneider, Jakob F.,Lauber, Markus B.,Muhr, Vanessa,Kratzer, Domenic,Paradies, Jan
, p. 4323 - 4327 (2011/07/08)
This paper focuses on readily accessible thiourea hydrogen bond catalysts derived from amino acids, whose steric and electronic features are modulated by their degree of substitution at the carbinol carbon center. These catalysts were applied in the asymmetric transfer hydrogenation of nitroolefins furnishing the chiral products in up to 99% yield and 86% enantiomeric excess. The proposed catalyst's mode of action is supported by mechanistic investigations.
Organocatalytic asymmetric transfer hydrogenation of nitroolefins
Martin, Nolwenn J. A.,Ozores, Lidia,List, Benjamin
, p. 8976 - 8977 (2008/02/10)
We describe a highly efficient and highly enantioselective Hantzsch ester mediated conjugate transfer hydrogenation of β,β-disubstituted nitroolefins that is catalyzed by a Jacobsen-type thiourea catalyst. Copyright
A General Method for the Preparation of 2,2-Disubstituted 1-Nitroalkenes
Denmark, Scott E.,Marcin, Lawrence R.
, p. 3850 - 3856 (2007/10/02)
A general and expeditious route for the preparation of functionalized 2,2-disubstituted 1-nitroalkenes has been developed.Conjugate 1,4-addition of complex zinc cuprates (RCu(CN)ZnI) to easily obtained (E)-1-nitroalkenes, followed by trapping with phenylselenenyl bromide and subsequent oxidative elimination, afforded the corresponding 2,2-disubstituted 1-nitroalkenes in good yields. 2-Alkyl-2-aryl- and 2,2-dialkyl nitroalkenes 4b-g were prepared in 76-88percent yield and obtained as E/Z isomeric mixtures, slightly favoring the Z isomer (ca. 1.0:1.5, E/Z).
Asymmetric Reduction of Nitro Olefins by Fermenting Bakers' Yeast
Ohta, Hiromichi,Kobayashi, Naoki,Ozaki, Kazuhiko
, p. 1802 - 1804 (2007/10/02)
Reduction of a number of 1-nitro-1-alkenes by fermenting bakers' yeast has been found to be enantioselective, resulting in the formation of optically active 1-nitroalkanes.In most cases, optical purities of the products determined by HPLC analysis of MTPA amides were as high as 83-98percent ee.The optimum rate of conversion was obtained when the reaction was carried out at pH 8 and low concentration of substrates.The absolute configuration of resulting (+)-1-nitro-2-phenylpropane was determined to be R by comparing the specific rotation with that of an authentic specimen after reductive hydrolysis to the corresponding aldehyde.
