619-56-7Relevant academic research and scientific papers
Advantage of anaerobic conditions in the highly enantioselective synthesis of α,α-dialkyl-α-amino acids by chiral phase-transfer catalysis
Ooi,Takeuchi,Ohara,Maruoka
, p. 1185 - 1187 (2001)
Intervention of the enolate oxidation in the catalytic asymmetric phase-transfer alkylation of protected α-amino acid derivatives under aerobic conditions has been addressed, and anaerobic conditions have been introduced to obtain synthetically satisfactory chemical yields as well as a high level of enantioselectivity.
Green and efficient Beckmann rearrangement by Cu(II) contained nano-silica triazine based dendrimer in water
Bahreininejad, Mohammad Hasan,Moeinpour, Farid
, p. 893 - 901 (2021/01/12)
In this research, a Cu(II) contained nano-silica triazine based dendrimer was prepared, characterized, and utilized as a retrievable catalytic system (Cu(II)-TrDen@nSiO2) for green formation of primary amides in water at room temperature. The structure of nanoparticles was fully characterized by using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetry analysis (TGA). The results revealed that the nanoparticles have spherical morphology and an average size of around 40 nm. The analysis also illustrated that the copper nanoparticles had been successfully loaded on the nitrogen-rich dendritic structure with a uniform distribution. The inductively coupled plasma analysis showed that about 0.67 mmol/g of Cu was loaded on the Cu(II)-TrDen@nSiO2 support. Mild reaction conditions, excellent yields, environment-friendly synthesis, and easily prepared starting materials are the key features of the present method. The catalyst is easily removed from the reaction media using a simple filtration and can be re-used at least five times without any considerable loss of its catalytic activity.
Process Development of the Copper(II)-Catalyzed Dehydration of a Chiral Aldoxime and Rational Selection of the Co-Substrate
Gr?ger, Harald,Nonnhoff, Jannis
, (2021/12/14)
The access towards chiral nitriles remains crucial in the synthesis of several pharmaceuticals. One approach is based on metal-catalyzed dehydration of chiral aldoximes, which are generated from chiral pool-derived aldehydes as substrates, and the use of a cheap and readily available nitrile as co-substrate and water acceptor. Dehydration of N-acyl α-amino aldoximes such as N-Boc-l-prolinal oxime catalyzed by copper(II) acetate provides access to the corresponding N-acyl α-amino nitriles, which are substructures of the pharmaceuticals Vildagliptin and Saxagliptin. In this work, a detailed investigation of the formation of the amide as a by-product at higher substrate loadings is performed. The amide formation depends on the electronic properties of the nitrile co-substrate. We could identify an acceptor nitrile which completely suppressed amide formation at high substrate loadings of 0.5 m even when being used with only 2 equivalents. In detail, utilization of trichloroacetonitrile as such an acceptor nitrile enabled the synthesis of N-Boc-cyanopyrrolidine in a high yield of 92 % and with full retention of the absolute configuration.
Visible light-mediated synthesis of amides from carboxylic acids and amine-boranes
Chen, Xuenian,Kang, Jia-Xin,Ma, Yan-Na,Miao, Yu-Qi
supporting information, p. 3595 - 3599 (2021/06/06)
Here, a photocatalytic deoxygenative amidation protocol using readily available amine-boranes and carboxylic acids is described. This approach features mild conditions, moderate-to-good yields, easy scale-up, and up to 62 examples of functionalized amides with diverse substituents. The synthetic robustness of this method was also demonstrated by its application in the late-stage functionalization of several pharmaceutical molecules.
Design of gp120 HIV-1 entry inhibitors by scaffold hopping via isosteric replacements
Ahmed, Shahad,Altieri, Andrea,Belov, Dmitry S.,Curreli, Francesca,Debnath, Asim K.,Iusupov, Ildar R.,Kurkin, Alexander V.,Manasova, Ekaterina V.,Markov, Pavel O.,Spiridonov, Evgeniy A.
, (2021/07/13)
We present the development of alternative scaffolds and validation of their synthetic pathways as a tool for the exploration of new HIV gp120 inhibitors based on the recently discovered inhibitor of this class, NBD-14136. The new synthetic routes were based on isosteric replacements of the amine and acid precursors required for the synthesis of NBD-14136, guided by molecular modeling and chemical feasibility analysis. To ensure that these synthetic tools and new scaffolds had the potential for further exploration, we eventually tested few representative compounds from each newly designed scaffold against the gp120 inhibition assay and cell viability assays.
Cu(II)-promoted oxidative C-N bond cleavage of N-benzoylamino acids to primary aryl amides
Zhou, Liandi,Liu, Wei,Zhao, Yongli,Chen, Junmin
, p. 52 - 62 (2021/02/06)
A novel protocol for CuCl2-promoted oxidative C-N bond cleavage of N-benzoyl amino acids was developed. It is the first example of using accessible amino acid as an ammonia synthetic equivalent for the synthesis of primary aryl amides via CuCl2-promoted oxidative C-N bond cleavage reaction. The present protocol shows excellent functional group tolerance and provides an alternative method for the synthetic of primary aryl amides in 84-96% yields.
Activated Mont K10-Carbon supported Fe2O3: A versatile catalyst for hydration of nitriles to amides and reduction of nitro compounds to amines in aqueous media
Rahman, Taskia,Borah, Geetika,Gogoi, Pradip K
, (2021/03/14)
The iron oxide was successfully supported on activated clay/carbon through an experimentally viable protocol for both hydrations of nitrile to amide and reduction of nitro compounds to amines. The as-prepared catalyst has been extensively characterised by XPS, SEM-EDX, TEM, TGA, BET surface area measurements and powdered X-ray diffraction (PXRD). A wide variety of substrates could be converted to the desired products with good to excellent yields by using water as a green solvent for both the reactions. The catalyst was recyclable and reusable up to six consecutive cycles without compromising its catalytic proficiency. Graphical abstract: Activated Mont K10 carbon-supported Fe2O3 is a very efficient and versatile heterogeneous catalytic system for hydration of nitriles to amides and reduction of nitro compounds to amines and can be reused up to six consecutive cycles without significant loss in catalytic activity.[Figure not available: see fulltext.].
Manganese-Pincer-Catalyzed Nitrile Hydration, α-Deuteration, and α-Deuterated Amide Formation via Metal Ligand Cooperation
Ben-David, Yehoshoa,Diskin-Posner, Yael,Kar, Sayan,Milstein, David,Zhou, Quan-Quan,Zou, You-Quan
, p. 10239 - 10245 (2021/08/24)
A simple and efficient system for the hydration and α-deuteration of nitriles to form amides, α-deuterated nitriles, and α-deuterated amides catalyzed by a single pincer complex of the earth-abundant manganese capable of metal-ligand cooperation is reported. The reaction is selective and tolerates a wide range of functional groups, giving the corresponding amides in moderate to good yields. Changing the solvent from tert-butanol to toluene and using D2O results in formation of α-deuterated nitriles in high selectivity. Moreover, α-deuterated amides can be obtained in one step directly from nitriles and D2O in THF. Preliminary mechanistic studies suggest the transformations contributing toward activation of the nitriles via a metal-ligand cooperative pathway, generating the manganese ketimido and enamido pincer complexes as the key intermediates for further transformations.
CuO-decorated magnetite-reduced graphene oxide: a robust and promising heterogeneous catalyst for the oxidative amidation of methylarenes in waterviabenzylic sp3C-H activation
Ebrahimi, Edris,Khalafi-Nezhad, Ali,Khalili, Dariush,Rousta, Marzieh
, p. 20007 - 20020 (2021/11/12)
A magnetite-reduced graphene oxide-supported CuO nanocomposite (rGO/Fe3O4-CuO) was preparedviaa facile chemical method and characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), UV-vis spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), Brunauer-Emmett-Teller (BET) analysis, vibrating-sample magnetometry (VSM), and thermogravimetric (TG) analysis. The catalytic activity of the rGO/Fe3O4-CuO nanocomposite was probed in the direct oxidative amidation reaction of methylarenes with free amines. Various aromatic and aliphatic amides were prepared efficiently at room temperature from cheap raw chemicals usingtert-butyl hydroperoxide (TBHP) as a “green” oxidant and low-toxicity TBAI in water. This method combines the oxidation of methylarenes and amide bond formation into a single operation. Moreover, the synthesized nanocomposites can be separated from the reaction mixtures using an external magnet and reused in six consecutive runs without a noticeable decrease in the catalytic activity.
Does electrophilic activation of nitroalkanes in polyphosphoric acid involve formation of nitrile oxides?
Aksenov, Alexander V.,Aksenov, Dmitrii A.,Aksenov, Nicolai A.,Kirilov, Nikita K.,Kurenkov, Igor A.,Nobi, Mezvah A.,Rubin, Michael,Skomorokhov, Anton A.,Sorokina, Elena A.
, p. 35937 - 35945 (2021/12/02)
The mechanistic rationale involving activation of nitroalkanes towards interaction with nucleophilic reagents in the presence of polyphosphoric acid (PPA) was re-evaluated. Could nitrile oxide moieties be formed during this process? This experiment demonstrates that at least in some cases this could happen, as generated nitrile oxides were successfully intercepted as adducts of [3 + 2] cycloadditions. This journal is
