20157-10-2Relevant academic research and scientific papers
Novel Tetrahydroquinazolinamines as Selective Histamine 3 Receptor Antagonists for the Treatment of Obesity
Kumar, Ajeet,Pasam, Venkata Reddy,Thakur, Ravi Kumar,Singh, Maninder,Singh, Kartikey,Shukla, Mahendra,Yadav, Anubhav,Dogra, Shalini,Sona, Chandan,Umrao, Deepmala,Jaiswal, Swati,Ahmad, Hafsa,Rashid, Mamunur,Singh, Sandeep K.,Wahajuddin, Muhammad,Dwivedi, Anil Kumar,Siddiqi, Mohammad Imran,Lal, Jawahar,Tripathi, Rama Pati,Yadav, Prem N.
, p. 4638 - 4655 (2019/05/17)
The histamine 3 receptor (H3R) is a presynaptic receptor, which modulates several neurotransmitters including histamine and various essential physiological processes, such as feeding, arousal, cognition, and pain. The H3R is considered as a drug target for the treatment of several central nervous system disorders. We have synthesized and identified a novel series of 4-aryl-6-methyl-5,6,7,8-tetrahydroquinazolinamines that act as selective H3R antagonists. Among all the synthesized compounds, in vitro and docking studies suggested that the 4-methoxy-phenyl-substituted tetrahydroquinazolinamine compound 4c has potent and selective H3R antagonist activity (IC50 0.04 μM). Compound 4c did not exhibit any activity on the hERG ion channel and pan-assay interference compounds liability. Pharmacokinetic studies showed that 4c crosses the blood brain barrier, and in vivo studies demonstrated that 4c induces anorexia and weight loss in obese, but not in lean mice. These data reveal the therapeutic potential of 4c as an anti-obesity candidate drug via antagonizing the H3R.
Triazole acetyl gold(III) catalyzed Meyer-Schuster rearrangement of propargyl alcohols
Yang, Yongchun,Shen, Yanan,Wang, Xiaoli,Zhang, Yao,Wang, Dawei,Shi, Xiaodong
supporting information, p. 2280 - 2282 (2016/05/10)
A new type triazole acetyl gold(III) was prepared and found to be an effective catalyst in Meyer-Schuster rearrangement of propargyl alcohols. The reactions proceeded well under much milder conditions to afford enones bearing a wide range of functional groups, thereby opening a new avenue for gold(III) catalysis. In addition, TriaAuCl2 catalyst was also effective on promotion of a-haloenones synthesis.
Intercepting the Gold-Catalysed Meyer-Schuster Rearrangement by Controlled Protodemetallation: A Regioselective Hydration of Propargylic Alcohols
Pennell, Matthew N.,Kyle, Michael P.,Gibson, Samantha M.,Male, Louise,Turner, Peter G.,Grainger, Richard S.,Sheppard, Tom D.
, p. 1519 - 1525 (2016/05/19)
The regioselective gold-catalysed hydration of propargylic alcohols to β-hydroxy ketones can be achieved by diverting the gold-catalysed Meyer-Schuster rearrangement through the addition of a protic additive with a pKa of 7-9 such as p-nitrophe
One-pot consecutive reactions based on the synthesis of conjugated enones by the re-catalysed meyer-schuster rearrangement
Mattia, Elio,Porta, Alessio,Merlini, Valentina,Zanoni, Giuseppe,Vidari, Giovanni
, p. 11894 - 11898 (2012/10/29)
Re catalysis in one-pot reactions: An atom-economical, one-pot strategy that involves alkyne deprotonation and a subsequent rhenium(V)-catalysed Meyer-Schuster rearrangement of the alkynol to provide α,β- unsaturated enones in high yield has been developed (see scheme). Subsequent in situ hydride reduction or Diels-Alder reaction of the enones provided products in good-to-high overall yields. Copyright
Gold- and silver-catalyzed reactions of propargylic alcohols in the presence of protic additives
Pennell, Matthew N.,Turner, Peter G.,Sheppard, Tom D.
, p. 4748 - 4758 (2012/05/04)
A wide range of primary, secondary and tertiary propargylic alcohols undergo a Meyer-Schuster rearrangement to give enones at room temperature in the presence of a gold(I) catalyst and small quantities of MeOH or 4-methoxyphenylboronic acid. The syntheses of the enone natural products isoegomaketone and daphenone were achieved using this reaction as the key step. The rearrangement of primary propargylic alcohols can readily be combined in a one-pot procedure with the addition of a nucleophile to the resulting terminal enone, to give β-aryl, β-alkoxy, β-amino or β-sulfido ketones. Propargylic alcohols bearing an adjacent electron-rich aryl group can also undergo silver-catalyzed substitution of the alcohol with oxygen, nitrogen and carbon nucleophiles. This latter reaction was initially observed with a batch of gold catalyst that was probably contaminated with small quantities of silver salt.
Immobilized palladium nanoparticles on a silica-starch substrate (PNP-SSS): As an efficient heterogeneous catalyst for Heck and copper-free Sonogashira reactions in water
Khalafi-Nezhad, Ali,Panahi, Farhad
experimental part, p. 2408 - 2415 (2011/10/13)
This paper reports an efficient heterogeneous catalyst system based on the immobilization of Pd nanoparticles on a silica-starch substrate (PNP-SSS). The PNP-SSS is found as a highly effective recyclable catalyst in Heck and copper-free Sonogashira reactions. The silica-starch substrate (SSS) can stabilize the Pd nanoparticles effectively so that it can provide a platform and prevent the aggregation of nanoparticles and their separation from the substrate surface. It also provides suitable catalytic sites for reactions in aqueous media. The Heck and copper-free Sonogashira reactions are performed in the presence of a small amount of this catalyst in water as a green solvent. The catalyst can be reused more than six times with almost consistent efficiency and can be recovered by simple filtration.
Triazole-gold-promoted, effective synthesis of enones from propargylic esters and alcohols: A catalyst offering chemoselectivity, acidity and ligand economy
Wang, Dawei,Zhang, Yanwei,Harris, Alexandria,Gautam, Lekh Nath S.,Chen, Yunfeng,Shi, Xiaodong
supporting information; experimental part, p. 2584 - 2588 (2011/12/01)
The air, moisture and thermally stable 1,2,3-triazole coordinated gold(I) complexes (TA-Au) were revealed as the effective catalysts in promoting propargylic ester rearrangement and sequential allene hydration, giving the enones with excellent yields (up to 97% yields, 0.2% loading). The catalysts could also catalyze the more challenging Meyer-Schuster rearrangement (0.5% loading, up to 98% yields). The reported reaction confirmed TA-Au as a chemoselective catalyst in promoting alkyne activation with high efficiency and improved ligand economy. Copyright
[(NHC)AuI]-catalyzed formation of conjugated enones and enals: An experimental and computational study
Marion, Nicolas,Carlqvist, Peter,Gealageas, Ronan,De Fremont, Pierre,Maseras, Feliu,Nolan, Steven P.
, p. 6437 - 6451 (2008/02/13)
The [(NHC)AuI]-catalyzed (NHC = N-heterocyclic carbene) formation of α,β-unsaturated carbonyl compounds (enones and enals) from propargylic acetates is described. The reactions occur at 60°C in 8 h in the presence of an equimolar mixture of [(NHC)AuCl] and AgSbF6 and produce conjugated enones and enals in high yields. Optimization studies revealed that the reaction is sensitive to the solvent, the NHC, and, to a lesser extent, to the silver salt employed, leading to the use of [(ItBu)AuCl]/ AgSbF6 in THF as an efficient catalytic system. This transformation proved to have a broad scope, enabling the stereoselective formation of (E)-enones and -enals with great structural diversity. The effect of substitution at the propargylic and acetylenic positions has been investigated, as well as the effect of aryl substitution on the formation of cinnamyl ketones. The presence or absence of water in the reaction mixture was found to be crucial. From the same phenylpropargyl acetates, anhydrous conditions led to the formation of indene compounds via a tandem [3,3] sigmatropic rearrangement/intramolecular hydroarylation process, whereas simply adding water to the reaction mixture produced enone derivatives cleanly. Several mechanistic hypotheses, including the hydrolysis of an allenol ester intermediate and SN2′ addition of water, were examined to gain an insight into this transformation. Mechanistic investigations and computational studies support [(NHC)AuOH], produced in situ from [(NHC)AuSbF6] and H 2O, instead of cationic [(NHC)AuSbF6] as the catalytically active species. Based on DFT calculations performed at the B3LYP level of theory, a full catalytic cycle featuring an unprecedented transfer of the OH moiety bound to the gold center to the C≡C bond leading to the formation of a gold-allenolate is proposed.
