25268-06-8Relevant academic research and scientific papers
Acid activated montmorillonite K-10 mediated intramolecular acylation: Simple and convenient synthesis of 4-chromanones
Begum, Ayisha F.,Balasubramanian, Kalpattu K.,Shanmugasundaram, Bhagavathy
, (2021/09/13)
3-Aryloxyproionic acids undergo intramolecular cyclization in the presence of AA.Mont.K-10 in toluene under reflux for 30–45 min in good to excellent yields. Phenyl ring bearing various substituents at the ortho, meta, para positions undergo this cyclization reaction. This method involves simple work up and amenable for large scale preparations. The heterogeneous acid treated catalyst can be regenerated and used for up to three cycles with minimum loss of activity.
Addition of amines and phenols to acrylonitrile derivatives catalyzed by the POCOP-type pincer complex [{κP,κC, κP-2,6-(i-Pr2PO)2C6H 3}Ni(NCMe)][OSO2CF3]
Lefvre, Xavier,Durieux, Guillaume,Lesturgez, Stéphanie,Zargarian, Davit
experimental part, p. 1 - 7 (2011/03/23)
The pincer-type complex [{κP,κC, κP-2,6-(i-Pr2PO)2C6H 3}Ni(NCMe)][OSO2CF3] (1) can serve as a precatalyst for the regioselective, anti-Markovnikov addition of nucleophiles to activated olefins. The catalyzed additions of aliphatic amines to acrylonitrile, methacrylonitrile, and crotonitrile proceed at room temperature and give quantitative yields of products resulting from the formation of C-N bonds. On the other hand, aromatic amines or alcohols are completely inert toward methacrylonitrile and crotonitrile, and much less reactive toward acrylonitrile, requiring added base, heating, and extended reaction times to give good yields. The catalytic reactivities of 1 are thought to arise from the substitutional lability of the coordinated acetonitrile that allows competitive coordination of the nitrile moiety in the olefinic substrates; this binding enhances the electrophilicity of the CC moiety, rendering them more susceptible to attack by nucleophiles. In some cases, RCN → Ni binding results in double bond isomerization/migration (allyl cyanide) or attack of nucleophiles at the nitrile moiety (cinnamonitrile and 4-cyanostyrene). Reaction of morpholine with 1 at 60 °C led to formation of the amidine derivative 2 that has been characterized by X-ray crystallography.
Hydroamination and alcoholysis of acrylonitrile promoted by the pincer complex {κP,κC,κP-2,6- (Ph2PO)2C6H3}Ni(OSO 2CF3)
Salah, Abderrahmen B.,Offenstein, Caroline,Zargarian, Davit
experimental part, p. 5352 - 5364 (2011/12/13)
This report describes the catalytic activity of the pincer-type complex {κP,κC,κP-2,6-(Ph 2PO)2C6H3}Ni(OSO2CF 3) (1) in the anti-Markovnikov addition of aliphatic and aromatic amines and alcohols to acrylonitrile, crotonitrile, and methacrylonitrile. The influence of additives on the catalytic activities was investigated, and it was found that substoichiometric quantities of water promoted the C-N bond forming reactions catalyzed by 1, especially the reactions involving aromatic amines; in comparison, NEt3 had a less dramatic impact. The opposite pattern was observed for the alcoholysis of acrylonitrile promoted by 1: water had no beneficial effect on these reactions, while NEt3 proved to be a potent promoter. Another important difference between these reactions is that hydroamination works better with more nucleophilic amines, whereas the alcoholysis reactions work well with ArOH, CF3CH2OH, and ArCH2OH but not at all with the more nucleophilic aliphatic alcohols methanol, ethanol, and 2-propanol. Both hydroamination and alcoholysis proceed much better with acrylonitrile in comparison to its Me-substituted derivatives crotonitrile and methacrylonitrile. Under optimized conditions, precatalyst 1 promotes conjugate additions to acrylonitrile with catalytic turnover numbers of up to 100 (hydroamination) or higher (alcoholysis). Spectroscopic studies have established that the main Ni-containing species in the hydroamination reactions is a cationic adduct in which the olefinic substrate is bound to the Ni center via its nitrile moiety; this binding activates the double bond toward an outer-sphere nucleophilic attack by the amine (Michael addition). The solid-state structures of the cationic nitrile adducts [{κP, κC,κP-2,6-(Ph2PO)2C 6H3}Ni(NCR)][OSO2CF3] (R = Me (2a), CH2CH2N(H)Ph (2e)), which can be regarded as model complexes for the species involved in the hydroamination catalysis, have been elucidated. Also reported are the solid-state structures of the charge-neutral compound {κP,κC,κP-2,6-(i- Pr2PO)2C6H3}Ni(OSO 2CF3) and an octahedral Ni(II) species resulting from the aerobic/hydrolytic oxidation of 1.
Monomeric and dimeric nickel complexes derived from a pincer ligand featuring a secondary amine donor moiety
Spasyuk, Denis M.,Zargarian, Davit
experimental part, p. 6203 - 6213 (2010/08/21)
Reaction of NiBr2(CH3CN)x with the unsymmetrical pincer ligand m-(i-Pr2PO)(CH2NHBn)C 6H4 (Bn = CH2Ph) gives the complex (R,S)-κP,κC,κN-{2-(i-Pr 2PO),6-(CH2NHBn)-C6H3}Ni IIBr, 1, featuring an asymmetric secondary amine donor moiety. Deprotonation of the latter with methyl lithium gave a dark brown compound that could not be characterized directly, but fully characterized derivatives prepared from this compound indicate that it is the LiBr adduct of the 14-electron amido species [κP,κC, κN-{2-(i-Pr2PO),6-(CH2NBn)-C 6H3}Ni], 2. Thus, 2·LiBr reacts with water to regenerate 1, while reaction with excess benzyl or allyl bromide gave the POCN-type pincer complexes 3 and 4, respectively, featuring tertiary amine donor moieties. On the other hand, heating 2·LiBr at 60 °C led to loss of LiBr and dimerization to generate the orange crystalline compound [μN;κP,κC,κN- {2-(i-Pr2PO),6-(CH2NBn)-C6H3}Ni] 2, 5. Solid state structural studies show that 1, 3, and 4 are monomeric, square planar complexes involving one Ni?N interaction, whereas complex 5 is a C2-symmetric dimer involving four Ni?N interactions and a Ni2N2 core featuring a short Ni?Ni distance (2.51 A). Preliminary reactivity tests have shown that 5 is stable toward weak nucleophiles such as acetonitrile but reacts with strong nucleophiles such as CO or 2,6-Me2(C6H3)NC. Reactions with protic reagents showed that phthalimide appears to break the dimer to generate a monomeric species, whereas alcohols appear to leave the dimer intact, giving rise instead to adducts through N...H...O interactions. These ROH adducts of 5 were found to be active precatalysts for the alchoholysis of acrylonitrile with up to 2000 catalytic turnover numbers.
NOUVEAUX DERIVES DE LA BENZOPYRANNONE-4, A ACTIVITES ANALGESIQUE, ANTI-INFLAMMATOIRE ET ANTIAGREGANTE PLAQUETTAIRE
Darmanaden, R.,Dhanutirto, H.,Castel, J.,Loubatiere, J.,Flandre, O.
, p. 876 - 887 (2007/10/02)
A series of 35 new derivatives of 3-benzylidene benzopyran-4-one carboxylic acid was synthesized; their antiinflammatory and analgesic activities were investigated and compared with those of acetylsalicylic acid, phenylbutazone, ketoprofene and glafenine.Among these compounds, four were found to be more potent than the references compounds in tests of antiinflammatory and analgesic activity.Seven compounds were tested on rat blood platelet aggregation induced by ADP.From these tests, HD-039, HD-041, HD-044 and HD-049 appear to be promising antiinflammatory, analgesic and anticlotting agents, although this original series shows little structural analogy with classical non-steroidal antiinflammatory agents.
