2630-41-3Relevant academic research and scientific papers
Norbornanoid chiral ketones by desymmetrization of dibromoalkenes
Ko?ak, Ramazan,Borsato, Giuseppe,De Lucchi, Ottorino,Da?tan, Arif
, p. 537 - 545 (2014)
New optically active polycyclic ketones 6a-6d, amenable to a large variety of synthetic applications, have been prepared from readily available 2,3-dibromonorbornene and analogs (Scheme 2) via desymmetrization with (-)-ephedrine, followed by hydrolysis under mild acidic conditions. At variance with substrates 4a-4d, the sterically hindered norbornene derivative 4e reacts with the solvent N-methylpyrrolidin-2-one (NMP) leading to the formation of the unusual cyclopropanoid products 8a and 8b. Copyright
Discovery of dual Axl/VEGF-R2 inhibitors as potential anti-angiogenic and anti-metastatic drugs for cancer chemotherapy
Goff, Dane,Zhang, Jing,Heckrodt, Thilo,Yu, Jiaxin,Ding, Pingyu,Singh, Raj,Holland, Sacha,Li, Weiqun,Irving, Mark
, p. 3766 - 3771 (2017)
Axl tyrosine kinase has been shown to be involved in multiple pathways contributing to tumor development, angiogenesis, and metastasis. High Axl expression has been observed in many human tumors where it appears to confer aggressive tumor behavior. Here we present several series of dual Axl-VEGF-R2 kinase inhibitors based on extensive optimization of an acyl diaminotriazole. It was hypothesized that dual inhibition of these two receptor tyrosine kinases may have a synergistic affect in inhibiting tumor angiogenesis and metastasis. One of these molecules, R916562 showed comparable activity to Sunitinib in two mouse tumor xenograft models and a mouse corneal micropocket model.
Catalytic alcohol oxidation using cationic Schiff base manganeseIII complexes with flexible diamino bridge
Kakavand, Meysam,Mastrorilli, Piero,Mesto, Ernesto,Neshat, Abdollah,Osanlou, Farzane,Schingaro, Emanuela,Todisco, Stefano
, (2020/11/04)
Four Schiff base manganese(III) complexes with derivatives of [(R,R)-N,N’-bis(salicy1idene)-1,2-cyclohexanediaminato)] including substituents on salicylaldehyde such as 3-methoxy, 3,5-di-tert-butyl and 3,5-chloro were synthesized and characterized using a combination of IR, UV–Vis, and HR ESI-MS techniques. The catalytic activity of these complexes was tested in the oxidation of 1-phenylethanol to acetophenone, revealing very good performances for all of the four manganese complexes. The catalytic reactions were carried out in the presence of tert-butyl hydroperoxide (TBHP) as oxidant and imidazole as co-catalyst. Complex Mn-4, bearing electron withdrawing [(R,R)-N,N’-bis(3,5-di-chloro-salicylidene)-1,2-cyclohexanediaminato)] ligand was found to be the most stable of the tested Mn(III) complexes and was selected for the oxidation of several primary and secondary alcohols.
Aerobic oxidation and oxidative esterification of alcohols through cooperative catalysis under metal-free conditions
Karimi, Babak,Ghahremani, Mina,Vali, Hojatollah,Ciriminna, Rosaria,Pagliaro, Mario
supporting information, p. 8897 - 8900 (2021/09/10)
The ABNO@PMO-IL-Br material obtained by anchoring 9-azabicyclo[3.3.1]nonane-3-oneN-oxyl (keto-ABNO) within the mesopores of periodic mesoporous organosilica with bridged imidazolium groups is a robust bifunctional catalyst for the metal-free aerobic oxidation of numerous primary and secondary alcohols under oxygen balloon reaction conditions. The catalyst, furthermore, can be successfully employed in the first metal-free self-esterification of primary aliphatic alcohols affording valued esters.
A Structural View on the Stereospecificity of Plant Borneol-Type Dehydrogenases
Chánique, Andrea M.,Dimos, Nicole,Drienovská, Ivana,Calderini, Elia,Pantín, Mónica P.,Helmer, Carl P. O.,Hofer, Michael,Sieber, Volker,Parra, Loreto P.,Loll, Bernhard,Kourist, Robert
, p. 2262 - 2277 (2021/03/16)
The development of sustainable processes for the valorization of byproducts and other waste streams remains an ongoing challenge in the field of catalysis. Racemic borneol, isoborneol and camphor are currently produced from α-pinene, a side product from the production of cellulose. The pure enantiomers of these monoterpenoids have numerous applications in cosmetics and act as reagents for asymmetric synthesis, making an enzymatic route for their separation into optically pure enantiomers a desirable goal. Known short-chain borneol-type dehydrogenases (BDHs) from plants and bacteria lack the required specificity, stability or activity for industrial utilization. Prompted by reports on the presence of pure (?)-borneol and (?)-camphor in essential oils from rosemary, we set out to investigate dehydrogenases from the genus Salvia and discovered a dehydrogenase with high specificity (E>120) and high specific activity (>0.02 U mg?1) for borneol and isoborneol. Compared to other specific dehydrogenases, the one reported here shows remarkably higher stability, which was exploited to obtain the first three-dimensional structure of an enantiospecific borneol-type short-chain dehydrogenase. This, together with docking studies, led to the identification of a hydrophobic pocket in the enzyme that plays a crucial role in the stereo discrimination of bornane-type monoterpenoids. The kinetic resolution of borneol and isoborneol can be easily integrated into the existing synthetic route from α-pinene to camphor thereby allowing the facile synthesis of optically pure monoterpenols from an abundant renewable source.
Alcohol Oxidations by Schiff Base Manganese(III) Complexes
Neshat, Abdollah,Kakavand, Meysam,Osanlou, Farzane,Mastrorilli, Piero,Schingaro, Emanuela,Mesto, Ernesto,Todisco, Stefano
, p. 480 - 490 (2020/02/05)
Asymmetric Schiff base manganese(III) complexes involving salen ligands, N,N'-bis(salicylidene)2,3-diaminopyridine, N,N'-bis(3-methoxysalicylidene)2,3-diaminopyridine, N,N'-bis(3,5-di-tert-butylsalicylidene)2,3-diaminopyridine and N,N'-bis(3,5-di-chloro-salicylidene)2,3-diaminopyridine were prepared and their catalytic activity was investigated in the oxidation of some primary and secondary alcohols. During optimization of oxidation reactions, Mn-4, bearing electron withdrawing N,N'-Bis(3,5-di-chloro-salicylidene)2,3-diaminopyridine ligand, showed higher activity than other catalysts tested. The catalytic reactions were carried out in the presence of various oxidants such as oxygen, hydrogen peroxide or tert-butyl hydroperoxide (TBHP) and additives such as acetic acid and imidazole. The oxidant/additive combination of TBHP and imidazole was shown to be effective for the oxidation process and the degree of their impact on oxidation reaction was found highly dependent on a balanced ratio between them. Mn-4 was selected as the most effective catalyst under optimized reaction conditions and revealed efficient for the oxidation of secondary alcohols.
Oxidation of Alkenes by Water with H2 Liberation
Ben-David, Yehoshoa,Milstein, David,Tang, Shan
supporting information, p. 5980 - 5984 (2020/04/27)
Oxidation by water with H2 liberation is highly desirable, as it can serve as an environmentally friendly way for the oxidation of organic compounds. Herein, we report the oxidation of alkenes with water as the oxidant by using a catalyst combination of a dearomatized acridine-based PNP-Ru complex and indium(III) triflate. Compared to traditional Wacker-type oxidation, this transformation avoids the use of added chemical oxidants and liberates hydrogen gas as the only byproduct.
Chemoselective Continuous Ru-Catalyzed Hydrogen-Transfer Oppenauer-Type Oxidation of Secondary Alcohols
Labes, Ricardo,Battilocchio, Claudio,Mateos, Carlos,Cumming, Graham R.,De Frutos, Oscar,Rincón, Juan A.,Binder, Kellie,Ley, Steven V.
supporting information, p. 1419 - 1422 (2017/09/23)
A continuous flow method for the selective oxidation of secondary alcohols is reported. The method is based on an Oppenauer-type ruthenium-catalyzed hydrogen-transfer process that uses acetone as both solvent and oxidant. The process utilizes a low loading (1 mol%) of the commercially available ruthenium catalyst [Ru(p-cymene)Cl2]2 and triethylamine as a base and can be successfully applied to a range of different substrates, with a good level of functional group tolerance.
Nonheme iron complex-catalyzed efficient alcohol oxidation by t-BuOOH with N-hydroxyphthalimide (NHPI) as co-catalyst: Implication of high valent iron-oxo species
Bae, Jeong Mi,Lee, Myoung Mi,Lee, Seul Ah,Lee, Sun Young,Bok, Kwon Hee,Kim, Jinheung,Kim, Cheal
, p. 8 - 15 (2016/07/14)
Two iron catalysts ([Fe(bpc)Cl2][Et4N] (1a) and [Fe(Me2bpb)Cl2][Et3NH] (1b)) displayed efficient catalysis in oxidation of various alcohols to the corresponding carbonyl products using t-BuOOH as an oxidant in the presence of N-hydroxyphthalimide (NHPI) under mild conditions. 1a having an electron-withdrawing group showed a little better catalytic activity than that of 1b with an electron-donating group. The mechanistic studies through Hammett plot, deuterium isotope effect, and the use of 2-methyl-1-phenylprop-2-yl hydroperoxide (MPPH) as a mechanistic probe suggested that the reactive oxidants responsible for the alcohol oxidation possibly involved FeIV[Formula presented]), and phthalimide N-oxyl radical [Formula presented]. On the other hand, the presence of imidazole increased the heterolytic cleavage of Fe-OOR intermediate to form FeV[Formula presented] species and accelerated its [Formula presented] bond cleavage rate. In particular, the formation of FeV[Formula presented] intermediate via the heterolytic cleavage of Fe-OOR species in the presence of imidazole in the catalytic oxidation systems of nonheme iron complexes with t-BuOOH was substantialized, for the first time, to the best of our knowledge.
Efficient epoxide isomerization within a self-assembled hexameric organic capsule
Caneva, Thomas,Sperni, Laura,Strukul, Giorgio,Scarso, Alessandro
, p. 83505 - 83509 (2016/11/01)
The isomerization of epoxides to the corresponding carbonyl compounds is efficiently catalyzed by the supramolecular organic nano-capsule formed by the self-assembly of six resorcin[4]arene units. The capsule provides a combination of weak Br?nsted acidity and a suitable nano-environment that favors the metal-free isomerization reaction.
