Search results for "Nitroaldol reaction"
showing 10 items of 27 documents
ChemInform Abstract: A Catalytic Highly Enantioselective Direct Synthesis of 2-Bromo-2-nitroalkan-1-ols Through a Henry Reaction.
2009
Highly enantiomerically enriched 2-bromo-2-nitroalkan-1-ols are prepared by direct condensation of aliphatic and aromatic aldehydes with bromonitromethane in the presence of a catalytic amount of copper(II) acetate and a C1-symmetric camphor-derived amino pyridine ligand.
ChemInform Abstract: Enantioselective Addition of Nitromethane to 2-Acylpyridine N-Oxides. Expanding the Generation of Quaternary Stereocenters with …
2014
The direct asymmetric Henry reaction with prochiral ketones, leading to tertiary nitroaldols, is an elusive reaction so far limited to a reduced number of reactive substrates such as trifluoromethyl ketones or α-keto carbonyl compounds. Expanding the scope of this important reaction, the direct asymmetric addition of nitromethane to 2-acylpyridine N-oxides catalyzed by a BOX-Cu(II) complex to give the corresponding pyridine-derived tertiary nitroaldols having a quaternary stereogenic center with variable yields and good enantioselectivity, is described.
ChemInform Abstract: New Highly Asymmetric Henry Reaction Catalyzed by CuIIand a C1-Symmetric Aminopyridine Ligand, and Its Application to the Synthe…
2008
A new catalytic asymmetric Henry reaction has been developed that uses a C(1)-symmetric chiral aminopyridine ligand derived from camphor and picolylamine. A variety of aromatic, heteroaromatic, aliphatic, and unsaturated aldehydes react with nitromethane and other nitroalkanes in the presence of DIPEA (1.0 equiv), Cu(OAc)(2)*H(2)O (5 mol %), and an aminopyridine ligand (5 mol %) to give the expected products in high yields (up to 99 %), moderate-to-good diastereoselectivites (up to 82:18), and excellent enantioselectivities (up to 98 %). The reaction is air-tolerant and has been used in the synthesis of the antifungal agent miconazole.
Catalytic activity of a CuGHK peptide-based porous material
2021
The CuGHK peptide-based porous material with a periodic distribution of pockets decorated with lysine side chain active sites was synthesized using a room temperature one-step method and used as a heterogeneous organocatalyst. The pockets are capable of benzaldehyde molecule uptake and show high activity in the Henry reaction with nitromethane. Mechanistic pathways are investigated using an integrative experimental/computational approach.
Highly enantioselective aza-Henry reaction with isatin N-Boc ketimines.
2014
A highly enantioselective aza-Henry reaction with isatin N-Boc ketimines using a Cu(II)–BOX complex as a catalyst is described. The reaction, which does not require protection of the N1 atom, provides the corresponding nitroamines bearing a quaternary stereocentre with high yields and enantiomeric excesses (up to 99.9%).
Concise asymmetric synthesis of Linezolid through catalyzed Henry reaction
2013
A new asymmetric synthesis of the antibiotic Linezolid was performed through a copper-catalyzed Henry reaction as the key step. The use of camphor-derived aminopyridine ligands helped to improve the yields of the chiral precursor and to obtain Linezolid in good overall yield and enantiomeric excess.
A catalytic highly enantioselective direct synthesis of 2-bromo-2-nitroalkan-1-ols through a Henry reaction.
2008
Highly enantiomerically enriched 2-bromo-2-nitroalkan-1-ols are prepared by direct condensation of aliphatic and aromatic aldehydes with bromonitromethane in the presence of a catalytic amount of copper(II) acetate and a C1-symmetric camphorderived amino pyridine ligand. Blay Llinares, Gonzalo, Gonzalo.Blay@uv.es ; Hernandez Olmos, Victor, Victor.Hernandez@uv.es ; Pedro Llinares, Jose Ramon, Jose.R.Pedro@uv.es
Metal-Organic Frameworks as Versatile Heterogeneous Solid Catalysts for Henry Reactions
2021
Metal–organic frameworks (MOFs) have become one of the versatile solid materials used for a wide range of applications, such as gas storage, gas separation, proton conductivity, sensors and catalysis. Among these fields, one of the more well-studied areas is the use of MOFs as heterogeneous catalysts for a broad range of organic reactions. In the present review, the employment of MOFs as solid catalysts for the Henry reaction is discussed, and the available literature data from the last decade are grouped. The review is organized with a brief introduction of the importance of Henry reactions and structural properties of MOFs that are suitable for catalysis. The second part of the review dis…
Modular iminopyridine ligands. Application to the enantioselective copper(II)-catalyzed Henry reaction
2006
Abstract Chiral iminopyridines prepared in a modular fashion from monoterpenic (camphor-derived) ketones and pyridinylalkylamines catalyze the enantioselective Henry (nitro aldol) reaction between nitromethane and o -anisol in the presence of copper(II) acetate, with high yields and good ee (up to 86%) under straightforward experimental conditions without the need for air or moisture exclusion.
Enantioselective Henry reaction catalyzed with copper(II)–iminopyridine complexes
2007
Abstract Copper complexes of chiral iminopyridines prepared from camphane-derived ketones and picolylamine catalyzed the enantioselective Henry (nitroaldol) reaction between nitromethane and a number of aromatic and aliphatic aldehydes with high yields and good enantioselectivities. Iminopyridines derived from (1 R )-(+)-camphor and (1 S )-(+)-ketopinic acid gave the best results to afford the opposite enantiomers in each case, despite the fact they have the same stereochemical pattern at the camphane skeleton. The reactions were carried out without air or moisture exclusion.