The Experts below are selected from a list of 453 Experts worldwide ranked by ideXlab platform
Luiz F Silva - One of the best experts on this subject based on the ideXlab platform.
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a comparative study of thallium iii and iodine iii mediated ring contraction reactions for the synthesis of indane
New Journal of Chemistry, 2021Co-Authors: Luiz F Silva, Ajmir Khan, Muhammad RabnawazAbstract:Reported herein is a comparative study of the synthesis of indane via ring contraction reaction, mediated by iodine(III) and thallium(III). A series of protected 1,2-dihydronaphthalenes were synthesized and subjected to hydroxy(tosyloxy)iodobenzene (HTIB) and thallium(III) nitrate trihydrate (TTN) in trimethyl orthoformate (TMOF) to compare the percent yields provided by both oxidizing agents. The yields of the ring contracted products (Indanes) were in the range of 61–88% for reactions performed with TTN·3H2O in TMOF. However, the yields were found to be significantly lower (e.g., 18–34%) when using HTIB in TMOF with some addition products. This study provides an important development related to the efficacy of the two oxidizing agents for ring contraction reaction.
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metal free asymmetric synthesis of Indanes through chiral hypervalent iodine iii mediated ring contraction
ChemInform, 2016Co-Authors: Anees Ahmad, Luiz F SilvaAbstract:The iodine(III)-mediated asymmetric oxidative rearrangement of 1,2-dihydronaphthalenes was investigated to prepare optically active 1-substituted Indanes. The chiral hypervalent iodine species is generated in situ from a chiral aryl iodide, prepared in 94% yield in one step. This metal-free protocol was applied to different cyclic alkenes, substituted with oxygen, with nitrogen, or at position 1 with aryl or methyl. Indanes can be isolated as an acetal or alcohol in up to 78% ee.
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Metal-Free Asymmetric Synthesis of Indanes through Chiral Hypervalent Iodine(III)-Mediated Ring Contraction
2016Co-Authors: Anees Ahmad, Luiz F SilvaAbstract:The iodine(III)-mediated asymmetric oxidative rearrangement of 1,2-dihydronaphthalenes was investigated to prepare optically active 1-substituted Indanes. The chiral hypervalent iodine species is generated in situ from a chiral aryl iodide, prepared in 94% yield in one step. This metal-free protocol was applied to different cyclic alkenes, substituted with oxygen, with nitrogen, or at position 1 with aryl or methyl. Indanes can be isolated as an acetal or alcohol in up to 78% ee
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Ring Contraction of 1,2-Dihydronaphthalenes Promoted by Thallium(III) in Acetonitrile: A Diastereoselective Approach to Indanes
Synthesis, 2009Co-Authors: Helena M. C. Ferraz, Vânia M. T. Carneiro, Luiz F SilvaAbstract:trans-1,3-Disubstituted Indanes are conveniently accessed by a stereoselective ring contraction of 1,2-dihydronaphthalenes upon treatment with thallium(III) nitrate (TTN) in acetonitrile. Under these conditions, the oxidative rearrangement of either di- or trisubstituted double bonds is possible.
Ajmir Khan - One of the best experts on this subject based on the ideXlab platform.
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a comparative study of thallium iii and iodine iii mediated ring contraction reactions for the synthesis of indane
New Journal of Chemistry, 2021Co-Authors: Luiz F Silva, Ajmir Khan, Muhammad RabnawazAbstract:Reported herein is a comparative study of the synthesis of indane via ring contraction reaction, mediated by iodine(III) and thallium(III). A series of protected 1,2-dihydronaphthalenes were synthesized and subjected to hydroxy(tosyloxy)iodobenzene (HTIB) and thallium(III) nitrate trihydrate (TTN) in trimethyl orthoformate (TMOF) to compare the percent yields provided by both oxidizing agents. The yields of the ring contracted products (Indanes) were in the range of 61–88% for reactions performed with TTN·3H2O in TMOF. However, the yields were found to be significantly lower (e.g., 18–34%) when using HTIB in TMOF with some addition products. This study provides an important development related to the efficacy of the two oxidizing agents for ring contraction reaction.
Helen Sheridan - One of the best experts on this subject based on the ideXlab platform.
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bioactive Indanes insight into the bioactivity of indane dimers related to the lead anti inflammatory molecule ph46a
Journal of Pharmacy and Pharmacology, 2020Co-Authors: Kit Chan, Neil Frankish, Tao Zhang, Aoife Cannon, Jacintha Osullivan, Helen SheridanAbstract:OBJECTIVES PH46A (1) demonstrates significant anti-inflammatory activity in phenotypic models but its mechanism and site of action have been elusive. Current study focused on the bioactivity of PH46 (2) and related novel indane dimers (6-10) to investigate the impact of changes in substitution and stereochemistry at the C-1 and C-2 positions of the PH46 (2) scaffold. METHODS Cytotoxicity profiles of compounds were established using THP-1 macrophages and SW480 cells. Effects of the compounds were then evaluated at 10 µm using 5-lipoxygenase (LOX) and 15-LOX enzymes, and 5-LOX binding was evaluated in silico against NDGA, nitric oxide (NO) released from LPS-induced SW480 cells and cytokines in THP-1 macrophages (IL-6, IL-1β, TNF-α and IFN-γ) and in SW480 cells (IL-8). KEY FINDINGS PH46 (2) and 7 cause reduction in NO, inhibition of 5-LOX with high binding energy and no cytotoxicity effects in THP-1 macrophages and SW480 cell lines (up to 50 µm). The cytokine profiling of the series demonstrated inhibition of IL-6 and TNF-α in THP-1 macrophages together with IL-8 in SW480 cells. CONCLUSIONS The observed profile of cytokine modulation (IL-6/ TNF-α, IL-8) and inhibition of release of NO and 5-LOX may contribute to the in vivo effects demonstrated by indane dimers and PH46A (1) in murine models of colitis.
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6 methylamino hexane 1 2 3 4 5 pentanol 4 1s 2s 1 hydroxy 2 3 dihydro 1h 1 h 2 2 biinden 2 yl methyl benzoate ph46a a novel small molecule with efficacy in murine models of colitis
Journal of Medicinal Chemistry, 2012Co-Authors: Neil Frankish, Helen SheridanAbstract:The indane skeleton is found naturally and in several therapeutic molecules in medicinal chemistry. During our work on the anti-inflammatory activity of naturally occurring and synthetic Indanes, we have synthesized a novel indane scaffold that has been optimized for both anti-inflammatory activity and bioavailability. We have evaluated our lead molecule, PH46A, in in vivo models of inflammatory bowel disease (IBD), an area of considerable unmet clinical need; current therapies are often unable to control the course of the disease. The compound significantly reduced histological damage and serum amyloid A (SAA) levels in IL-10(-/-) colitis mice, was efficacious in the 5% dextran sulfate sodium (DSS) colitis model, and compared favorably with prednisolone in this model and supports its potential use to treat acute exacerbations of the disease. Further, the graded response to the compound may also lend itself to be used at a lower dose to maintain periods of remission.
Michael H Nantz - One of the best experts on this subject based on the ideXlab platform.
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synthesis of ethylene 1 η5 4 5 6 7 tetrahydro 1 indenyl 2 η5 4 5 6 7 tetrahydro 2 indenyl titanium dichloride the elusive isomer of the brintzinger type ansa titanocenes
Journal of Organic Chemistry, 2003Co-Authors: Patrick A Kelly, Gideon O Berger, Justin K Wyatt, Michael H NantzAbstract:We present a short synthesis of 1-(2-indenyl)-2-(3-indenyl)ethane (5) and a method for its conversion to the ansa-metallocene [ethylene(η5-inden-1-yl)(η5-inden-2-yl)]titanium dichloride (13). The synthetic strategy applied to prepare bisindene 5 relies on the efficient alkylation of 2-(phenylsulfonyl)indane followed by HMPA-assisted E1cB-elimination of phenylsulfinate. This tandem sequence circumvents the predisposition of indene to undergo C(1)-alkylation and enables access to C(2)-substituted indenes. The key step in the synthesis of the title ansa-titanocene (4) features a previously unreported equilibration step to generate the bis(indenide anion) of 5. Complexation with TiCl4·(THF)2 followed by hydrogenation of the product metallocene furnishes ansa-titanocene 4.
James F Wolfe - One of the best experts on this subject based on the ideXlab platform.
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synthesis of succinimido 3 4 b indane and 1 2 3 4 5 6 hexahydro 1 5 methano 3 benzazocine 2 4 dione by sequential alkylation and intramolecular arylation of enolates derived from n n n n tetramethylbutanediamides and n n n n tetramethylpentanediamides
Journal of Organic Chemistry, 1999Co-Authors: Sushama A Dandekar, Stacey N Greenwood, Thomas D Greenwood, Stephane Mabic, Joseph S Merola, James M Tanko, James F WolfeAbstract:The tricyclic title compounds, 4 and 5, were synthesized by initial alkylation of the lithium monoenolates of N,N,N‘,N‘-tetramethylbutanediamide (6) and N,N,N‘,N‘-tetramethylpentanediamide (19) with 2-iodobenzyl chloride in liquid NH3 at −60 °C to afford 2-(2-iodobenzyl)-N,N,N‘,N‘-tetramethylbutanediamide (9) and 2-(2-iodobenzyl)-N,N,N‘,N‘-tetramethylpentanediamide (20) in yields of 88 and 87%, respectively. Treatment of 9 with KNH2 in liquid NH3 resulted in formation and intramolecular arylation of the less-substituted α-enolate to produce trans-1,2-bis(N,N-dimethylcarboxamido)indane (10a) in 60% yield. Selective hydrolysis of 10a with aqueous Na2O2 gave trans-1-(N,N-dimethylcarboxamido)indane-2-carboxylic acid (17), which was then converted to bridged succinimide 4 by transformation to trans-1-(N,N-dimethylcarboxamido)indane-2-carboxamide (10c) followed by cyclization of this mixed primary/tertiary amide by means of NaH in refluxing THF. Treatment of 20 with KNH2 in liquid NH3 led to intramolecular aryl...
