14756-03-7Relevant academic research and scientific papers
Synthesis and Some Properties of 1-Fluoro-1-alken-3-ols
Tellier, Frederique,Sauvetre, Raymond
, p. 4223 - 4226 (1995)
The reduction of 1,1-difluoro-1-alken-3-ols with lithium tetrahydroaluminate is described. 1-Fluoro-1-alken-3-ols obtained can be transformed to enals or difluoromethylated allylic derivatives.
Naphthoxazoles and heterobenzoxazoles: Cholinesterase inhibition and antioxidant activity
?agud, Ivana,?kori?, Irena,Bur?ul, Franko
, p. 118 - 124 (2019)
Finding novel cholinesterase inhibitors that would be able to cross the blood–brain barrier, have favorable pharmacokinetic parameters, and reduce hepatotoxicity along with other side effects has been the main focus of investigations dealing with Alzheimer disease. In this study we evaluated cholinesterase inhibitory and antioxidant activity of seven oxazole derivatives. These compounds have been efficiently and sustainably prepared by photochemical electrocy-clization reaction. Various naphthoxazoles have been previously investigated as potential antibacterial, antituberculosis, and anticancer agents. They have also been tested for antioxidant activity, but never for cholinesterase inhibitory activity. Among the tested oxazole derivatives, fused heterobenzoxazole compounds with pyridine and thiophene moiety, oxazolo[5,4-h]isoquinoline, thieno[2’,3’:5,6]benzo[1,2-d]oxazole, and thieno[3’,2’:5,6]benzo[1,2-d]oxazole, showed the greatest potential for both cholinesterase inhibitory and antioxidant activity. Among them, thieno[2’,3’:5,6]benzo[1,2d]oxazole was found to be the best one.
The role of isomeric effects on the luminescence lifetimes and electrochemistry of oligothienyl-bridged dinuclear tris(2,2′-bipyridine) ruthenium(II) complexes
Steen, Robert O.,Nurkkala, Lasse J.,Angus-Dunne, Sarah J.,Schmitt, Chantal X.,Constable, Edwin C.,Riley, Mark J.,Bernhardt, Paul V.,Dunne, Simon J.
, p. 1784 - 1794 (2008)
The luminescence lifetimes (in CH3CN at room temperature) and electrochemical potentials (in CH3CN) of a range of mono- and bis(bidentate) 2,2′-bipyridine-capped oligothiophene-bridged Ru II complexes based on the 6-(2-thienyl)-2,2′-bipyridine and 4-(2-thienyl)-2,2′-bipyridine motifs have been measured. The redox potentials occurred in a very narrow range and showed only small shifts from that of [Ru(bpy)3]2+, which indicates that the inductive effects of the substituents on the 2,2′-bipyridine ligands are very similar across this series. In the complexes that incorporated a bithiophene moiety the oxidation of the bithienyl group occurred at higher potentials than the metal-centered RuIII/II oxidation. No or very weak interaction between the metal cores in the dinuclear complexes was observed. It was found that the luminescence lifetimes of the complexes where the attachment point of the oligothiophene bridge is in the 4-position of a 2,2′-bipyridine ligand were extended compared to [Ru(bpy)3]2+, whereas the luminescence was very short-lived (30 ns) or completely quenched in the complexes where the oligothiophene bridge was attached in the 6-position. The difference in lifetimes is probably due to steric interactions between the thienyl bridge and the auxiliary bipyridyl ligands, resulting in disturbances in coordination symmetry of the metal core. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
Method for preparing olefine aldehyde by catalyzing terminal alkyne or terminal conjugated eneyne and diphosphine ligand used in method
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Paragraph 0163; 0164, (2021/05/29)
The invention discloses a method for preparing olefine aldehyde by catalyzing terminal alkyne or terminal conjugated eneyne and a diphosphine ligand used in the method. According to the invention, indole-substituted phosphoramidite diphosphine ligand which is stable in air and insensitive to light is synthesized by utilizing a continuous one-pot method, and the indole-substituted phosphoramidite diphosphine ligand and a rhodium catalyst are used for jointly catalyzing to successfully achieve a hydroformylation reaction of aromatic terminal alkyne and terminal conjugated eneyne under the condition of synthesis gas for the first time, so that an olefine aldehyde structure compound can be rapidly and massively prepared, and particularly, a polyolefine aldehyde structure compound which is more difficult to synthesize in the prior art can be easily prepared and synthesized, and a novel method is provided for synthesis and modification of drug molecules, intermediates and chemical products.
Tandem oxidation-dehydrogenation of (hetero)arylated primary alcohols via perruthenate catalysis
Bettencourt, Christian J.,Chow, Sharon,Moore, Peter W.,Read, Christopher D.G.,Jiao, Yanxiao,Bakker, Jan Peter,Zhao, Sheng,Bernhardt, Paul V.,Williams, Craig M.
, p. 652 - 659 (2021/09/08)
Tandem oxidative-dehydrogenation of primary alcohols to give a,b-unsaturated aldehydes in one pot are rare transformations in organic synthesis, with only two methods currently available. Reported herein is a novel method using the bench-stable salt methyltriphenylphosphonium perruthenate (MTP3), and a new co-oxidant NEMO&middoPF6 (NEMO = N-ethyl-N-hydroxymorpholinium) which provides unsaturated aldehydes in low to moderate yields. The Ley-Griffith oxidation of (hetero)arylated primary alcohols with N-oxide co-oxidants NMO (NMO = N-methylmorpholine N-oxide)/NEMO, is expanded by addition of the N-oxide salt NEMO&middoPF6 to convert the intermediate saturated aldehyde into its unsaturated counterpart. The discovery, method development, reaction scope, and associated challenges of this method are highlighted. The conceptual value of late-stage dehydrogenation in natural product synthesis is demonstrated via the synthesis of a polyene scaffold related to auxarconjugatin B.
Highly Enantioselective Synthesis of Functionalized Glutarimide Using Oxidative N-Heterocyclic Carbene Catalysis: A Formal Synthesis of (?)-Paroxetine
Porey, Arka,Santra, Surojit,Guin, Joyram
supporting information, p. 5313 - 5327 (2019/04/16)
A simple yet highly effective approach toward enantioselective synthesis of trans-3,4-disubstituted glutarimides from readily available starting materials is developed using oxidative N-heterocyclic carbene catalysis. The catalytic reaction involves a formal [3 + 3] annulation between enals and substituted malonamides enabling the production of glutarimide derivatives in a single chemical operation via concomitant formation of C-C and C-N bonds. The reaction offers easy access to a broad range of functionalized glutarimides with excellent enantioselectivity and good yield. Synthetic application of the method is demonstrated via formal synthesis of (?)-paroxetine and other bioactive molecules.
Enantioselective Organocatalytic Enamine C?H Oxidation/Diels- Alder Reaction
D?ambaski, Zdravko,Tzaras, Dimitrios-Ioannis,Lee, Sunggi,Kokotos, Christoforos G.,Bondzic, Bojan P.
supporting information, p. 1792 - 1797 (2019/02/25)
α,β-unsaturated aldehydes have been traditionally used in LUMO lowering asymmetric aminocatalysis (iminium catalysis), while the use of saturated aldehydes as substrates in this type of catalysis has been elusive, until recently. Herein, we demonstrate that organic, single-electron oxidants in the presence of diarylprolinol silylether type catalysts serve as effective tools for the transformation of electron rich enamines to iminium ions which partake in a subsequent Diels-Alder reaction. This enantioselective one-pot transformation represents the first example of saturated aldehydes being used in domino Diels-Alder reaction processes and demonstrates the power of this protocol for construction of stereo-defined chiral compounds and building blocks. (Figure presented.).
Secondary amine-catalyzed [3 + 3] benzannulation to access polysubstituted benzenes through iminium activation
Jiang, Lin,Li, Hang,Zhou, Jiang-Feng,Yuan, Ming-Wei,Li, Hong-Li,Chuan, Yong-Ming,Yuan, Ming-Long
supporting information, p. 336 - 343 (2018/02/09)
An organocatalytic [3 + 3] benzannulation to access polysubstituted benzenes from readily available α,β-unsaturated aldehydes and 1,3-bis(phenylsulfonyl)propene or 4-sulfonylcrotonates is described. The key reaction step is considered to be the iminium ac
One-Pot l-Proline-Mediated Stereoselective α-C(sp2)–H Fluorination of α,β-Unsaturated Aldehydes through Methoxyfluorination–Elimination
Zhou, Jiadi,Jiang, Xinpeng,Jin, Can,Guo, Zhicheng,Su, Bin,Su, Weike
supporting information, p. 3631 - 3634 (2017/07/22)
A one-pot, two-step l-proline-mediated stereoselective α-C(sp2)–H fluorination of α,β-unsaturated aldehydes towards their corresponding (Z)-α-fluoro-α,β-unsaturated aldehydes has been developed. The first step utilises Selectfluor as a fluorinating agent in CH3NO2/MeOH forming (Z)-α-fluoro-α,β-unsaturated aldehydes and their corresponding dimethyl acetals through methoxyfluorination-elimination. In the second step, water is added to promote the hydrolytic cleavage of the dimethyl acetals. The obtained (Z)-α-fluoro-α,β-unsaturated aldehydes were smoothly reduced to the corresponding alcohols by using NaBH4.
Cascade reaction of propargylic alcohols with hydroxylamine hydrochloride: facile synthesis of α,β-unsaturated oximes and nitriles
Zhang, Qi,Zhang, Linjing,Tang, Chaojun,Luo, Huan,Cai, Xuediao,Chai, Yonghai
, p. 6935 - 6942 (2016/10/14)
We have developed an easy and practical method for the synthesis of α,β-unsaturated oximes and nitriles from readily available propargylic alcohols with hydroxylamine hydrochloride (NH2OH·HCl) under metal-free conditions. By using or not using p-toluenesulfonyl chloride (p-TsCl) as the dehydrating promoter, the desired nitriles or oximes could be obtained, respectively via a three-step one-pot or two-step one-pot process in moderate to excellent yields with good functional group compatibility.
