5032-08-6Relevant articles and documents
Lewis Acid Assisted Electrophilic Fluorine-Catalyzed Pinacol Rearrangement of Hydrobenzoin Substrates: One-Pot Synthesis of (±)-Latifine and (±)-Cherylline
Shi, Hui,Du, Chuan,Zhang, Xinhang,Xie, Fukai,Wang, Xiaoyu,Cui, Shanshan,Peng, Xiaoshi,Cheng, Maosheng,Lin, Bin,Liu, Yongxiang
, p. 1312 - 1319 (2018/02/09)
A microwave-irradiated solvent-free pinacol rearrangement of hydrobenzoin substrates catalyzed by a combination of N-fluorobenzenesulfonimide and FeCl3·6H2O was developed. Its selectivity was first investigated by density functional theory (DFT) calculations. Then the functional group tolerance was examined by synthesizing a series of substrates designed based on the insight provided by the DFT calculations. The application of the methodology was demonstrated by the efficient one-pot synthesis of (±)-latifine and (±)-cherylline, both are 4-aryltetrahydroisoquinoline alkaloids isolated from Amaryllidacecae plants.
A gold catalytic pinacone method of rearrangement of
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Paragraph 0027; 0028; 0029; 0030; 0031, (2017/11/22)
The invention provides a method used for catalytic rearrangement of pinacol with gold. A reaction general formula is disclosed in the invention, wherein R1, R2, R3, and R4 may be common alkyl, cycloalkyl, and aromatic rings. A gold catalyst needed by reac
Structure–Activity Relationship Studies on 6,7-Dimethoxy-2-phenethyl-1,2,3,4-tetrahydroisoquinoline Derivatives as Multidrug Resistance Reversers
Teodori, Elisabetta,Dei, Silvia,Bartolucci, Gianluca,Perrone, Maria Grazia,Manetti, Dina,Romanelli, Maria Novella,Contino, Marialessandra,Colabufo, Nicola Antonio
, p. 1369 - 1379 (2017/09/01)
A series of derivatives were synthesized and studied with the aim to investigate the structure–activity relationships of the two P-glycoprotein (P-gp) modulators elacridar and tariquidar. Then, different aryl-substituted amides were inserted, and to explore the effects of varying the amide function, the corresponding isosteric ester derivatives and some alkylamine analogues were synthesized. The new compounds were studied to evaluate their P-gp interaction profile and selectivity toward the two other ABC transporters, multidrug-resistance-associated protein-1 (MRP-1) and breast cancer resistance protein (BCRP). Investigation of the chemical stability of the amide and ester derivatives toward spontaneous or enzymatic hydrolysis showed that these compounds were stable in phosphate-buffered saline and human plasma. This study allowed us to evaluate the selectivity of the three series on the three efflux pumps and to propose the structural requirements that define the P-gp interaction profile. We identified two P-gp substrates, a P-gp inhibitor, and three ester derivatives that were active on BCRP, which opens a new scenario in the development of ligands active toward this pump.
α,α-Diarylethylene Glycols as Valuable Precursor for Synthesis of 1,1-Diarylethenes and α,α-Diaryl Acetaldehydes
Tiwari, Praveen Kumar,Sivaraman, Balasubramaniam,Aidhen, Indrapal Singh
, p. 3594 - 3605 (2017/07/22)
Towards assembling of diarylmethine unit present in biologically important molecules, we have developed a new Weinreb Amide (WA) based building block derived from glycolic acid. The WA functionality present in this building block permits the sequential addition of various arylmagnesium bromide reagents in a controlled manner that enables assembly of a diarylmethine unit. The developed synthetic route provides easy access to important diarylethenes and α,α-diarylethylene glycols. The synthesized α,α-diarylethylene glycols provide access to synthetically important symmetrical and unsymmetrical α,α-diaryl acetaldehydes as valuable intermediates.
On the photodegradation of some 2H-chromene derivatives in fluid solution or in polyurethane matrix
Alberti, Angelo,Campredon, Mylene,Demadrille, Renaud
experimental part, p. 552 - 561 (2011/06/25)
The time profile of the optical density was monitored during the photodegradation of three derivatives of 2,2-diphenyl-2H-naphtho[1,2-b]pyran (1), namely 2,2-bis(4-methoxyphenyl)-5,6-dimethyl-2H-naphtho[1,2-b]pyran (2), 2,2-diphenyl-5-[(ethoxycarbonyl)methoxycarbonyl]-8-methyl-2H-naphtho[1,2-b] pyran (3), and 3,3-bis(4-methoxyphenyl)-6,11-dimethyl-13-hydroxy-13-isopropyl- 3H-indeno[2,1-f ]naphtho[1,2-b]pyran (4) either in toluene solution or in a polyurethane matrix. The photoproducts were identified using HPLC, GC/MS, and direct insertion MS techniques. High molecular weight oxygenated derivatives and new photoproducts deriving from a secondary oxidative pathway were characterized along with expected degradation derivatives. Some of the photoproducts considered responsible for the yellowing of the examined materials were identified. The effect exerted by two additives generally considered to have an inhibiting action toward radical processes was also evaluated.
Tandem pinacol coupling-rearrangement of aromatic aldehydes with hydrogen catalyzed by a combination of a platinum complex and a polyoxometalate
Branytska, Olena,Shimon, Linda J. W.,Neumann, Ronny
, p. 3957 - 3959 (2008/10/09)
Together with a strongly oxidizing polyoxometalate, H5PV 2Mo10O40, PtII(N-(2,6- diisopropylphenyl)pyrazin-2-ylmethanimine)Cl2 forms a combined catalyst that was active in the tandem pinacol coupling-rearrangement of aryl aldehydes to give mostly the corresponding diarylacetaldehyde in high yields using molecular hydrogen as the reducing agent. The Royal Society of Chemistry.
Zeolite-Promoted Oxidations of 1,1-Diarylethylenes
Clennan, Edward L.,Pan, Gui-Ian
, p. 4979 - 4982 (2007/10/03)
(Equation Presented) The intrazeolite photooxygenations of four diarylethylenes have been examined. Several intermediates, including an epoxide, have been identified by comparison to independently synthesized samples. Aldehyde intermediates were shown to undergo intrazeolite Norrish type I cleavages in competition with a novel new photooxygenation/autoxidation reaction.
Use of 4-substituted tetrahydropyridines for making medicines acting on TGF-β1
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Page column 14, (2010/02/04)
The invention relates to the use of a compound of formula (I): for the preparation of pharmaceutical compositions for increasing the circulating, cellular and extracellular levels of TGF-β1.
Mechanism of manganese porphyrin-catalyzed oxidation of alkenes. Role of manganese(IV)-oxo species
Arasasingham, Ramesh D.,He, Gong-Xin,Bruice, Thomas C.
, p. 7985 - 7991 (2007/10/02)
The mechanism for the bimolecular reaction of meso-tetrakis(2,6-dichlorophenyl)porphinato-oxo-manganese-(IV), [(C18TPP)MnIV(O)], with alkenes has been investigated by kinetics and product identification. Kinetic studies were carried out with 11 alkenes (trear-4-methoxystilbene, cis-4-methoxystilbene, 1,4-diphenyl-1,3-butadiene, 4-methoxystyrene, 1,1-diphenylethylene, 4-methylstyrene, 2,3-dimethyl-2-butene, trans-stilbene, cis-stilbene, styrene, 4-acetoxystyrene) in methylene chloride solution (30 °C) in air. The reactivities of the alkenes show that the trans alkenes are slightly more reactive than their cis isomers and that electron releasing substituents slightly favor the reaction. The second-order rate constant values (k2) correlate well with the potentials for the le- oxidation (E1/2) of the alkenes. The slope of the linear plot of log k2 vs E1/2for the series of alkenes (slope = -0.89 V-1) indicate that a mechanism of epoxidation involving rate-determining formation of an alkene derived π-cation-radical is unlikely. For the reaction with substituted styrenes, the linear free-energy relationship of log k2 vs σ (p+ = -0.99) supports a transition state with very little charge separation. Product yields determined for the reactions with cis-stilbene, transstilbene, 2,3-dimethyl-2-butene, cis-4-methoxystilbene, and trans-4-methoxystilbene are in accord with a mechanism involving the formation of a (porph)MnIIIOCC? radical intermediate. Thus, the products of cis-stilbene oxidation under aerobic conditions are cis-stilbene oxide (7%), frans-stilbene oxide (5%), and benzaldehyde (3%). Comparison with the reactions carried out under conditions favoring the transiently stable manganese(V)-oxo species showed more efficient epoxidation with a greater degree of stereospecificity. In a search for radical intermediates the cis olefinic substrate (Z)-1,2-bis(trans-2,trans-3-diphenylcyclopropyl)ethene was used as a radical trap. While no epoxide products were found, a polar oxygen-containing product resulting from the opening of one trans-2,trans-3-diphenylcyclopropyl ring by a cyclopropylcarbinyl to homoallylcarbinyl radical rearrangement (CPCRR) was detected supporting the formation of a neutral carbon radical species.
One-pot conversion of α-substituted arylacetaldehydes into α-dicarbonyl compounds
Lopez, Luigi,Mele, Giuseppe,Nacci, Angelo,Troisi, Luigino
, p. 3897 - 3900 (2007/10/02)
α-dicarbonyl compounds 7-12 can be easily prepared by reaction of methylene chloride solutions of several α-substituted arylacetaldehydes 1-6 with a slight excess of tris-(o,p-dibromophenyl) ammoniumyl hexachloro antimonate A.
