55568-96-2Relevant academic research and scientific papers
Catalytic Enantioselective Synthesis of 2-Aryl Chromenes and Related Phosphoramidite Ligands and Catalyst Compounds
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, (2015/11/24)
Methods to access 2-aryl chromene compounds via an asymmetric catalytic process.
Towards the discovery of drug-like epigallocatechin gallate analogs as Hsp90 inhibitors
Bhat, Rohit,Adam, Amna T.,Lee, Jungeun Jasmine,Gasiewicz, Thomas A.,Henry, Ellen C.,Rotella, David P.
, p. 2263 - 2266 (2014/05/20)
(-)-Epigallocatechin gallate (EGCG) is the major flavonoid of green tea and has been widely explored for a range of biological activities including anti-infective, anti-inflammatory, anti-cancer, and neuroprotection. Existing structure-activity data for EGCG has been largely limited to exploration of simple ethers and hydroxyl deletion. EGCG has poor drug-like properties because of multiple phenolic hydroxyl moieties and a metabolically labile ester. This work reports a substantial expansion of structure-activity understanding by exploring a range of semi-synthetic and synthetic derivatives with ester replacements and variously substituted aromatic and alicyclic groups containing more drug-like substituents. Structure-activity relationships for these molecules were obtained for Hsp90 inhibition. The results indicate that amide and sulfonamide linkers are suitable ester replacements. Hydroxylated aromatic rings and the cis-stereochemistry in EGCG are not essential for Hsp90 inhibition. Selected analogs in this series are more potent than EGCG in a luciferase refolding assay for Hsp90 activity.
Catalytic enantioselective synthesis of 2-aryl-chromenes
Zeng, Bi-Shun,Yu, Xinyi,Siu, Paul W.,Scheidt, Karl A.
, p. 2277 - 2281 (2014/05/20)
An enantioselective Pd-catalyzed 6-endo-trig reaction for the synthesis of 2-aryl-chromenes has been developed. A systematic optimization of a TADDOL-derived ligand set resulted in the identification of a novel monodentate phosphoramidite-palladium catalyst that accesses 2-aryl-2H-chromenes with high yield and enantioselectivity under mild conditions. The products obtained from this method can be transformed into biologically active compounds through functionalization of the chromene alkene. This journal is the Partner Organisations 2014.
Improved synthesis of structural analogues of (-)-epicatechin gallate for modulation of staphylococcal β-lactam resistance
Anderson, James C.,Grounds, Helen,Reeves, Suzanna,Taylor, Peter W.
, p. 3485 - 3490 (2014/05/06)
The high-yielding synthesis of enantiomerically pure epicatechin gallate analogues where the A and/or B-ring hydroxylation is reduced or altered has been achieved by optimising routes to the catechin stereochemistry. The B-ring analogues were synthesised by using an electrophilic ring closure onto an enantiomerically enriched epoxide as a key step. The A and B-ring hydroxyl-deleted analogues were synthesised through a Mitsunobu cyclisation. For the B-ring analogues, the anti- (catechin) stereochemistry was converted to the syn- (epicatechin) stereochemistry by a known oxidation/reduction protocol. Absolute stereochemistry was derived from either a Sharpless epoxidation or asymmetric dihydroxylation.
Enantioselective synthesis of flavan-3-ols using a mitsunobu cyclization
Krohn, Karsten,Ahmed, Ishtiaq,John, Markus
experimental part, p. 779 - 786 (2009/09/06)
The synthesis of four flavan-3-ols with different substitution patterns and electron densities has been achieved in high stereo- and regioselectivity by a one-step Mitsunobu reaction from the corresponding diols, which were prepared by enantioselective Sharpless dihydroxylation of suitable olefins. The six-membered flavan-3-ols were the only cyclization products and the theoretically possible formation of five-membered rings during the Mitsunobu cyclization was not observed. The flavanols are important starting materials for the synthesis of dimers such as the procyanidins or other coupling products such as the flavan part of the potent DNA polymerase β inhibitor myristinin A. The enantioselectivities of both the Sharpless dihydroxylation and the Mitsunobu cyclization steps were monitored by chiral HPLC. Georg Thieme Verlag Stuttgart New York.
Reactions of Flav-2-enes and Flav-2-en-4-ones (Flavones)
Bird, T. Geoffrey C.,Brown, Ben R.,Stuart, Ian A.,Tyrrell, William R.
, p. 1831 - 1846 (2007/10/02)
Flav-2-enes, flavones, and 3-alkyl ethers of flavonols add alcohols and carboxylic acids in the presence of N-bromosuccinimide to give 2-alkoxy- and 2-acyloxy-3-bromoflavans which provide routes to cis-3-bromoflavans by reduction and to 3,4-diols by elimination and reaction with osmium tetraoxide.The 2-acyloxyflavans react with alcohols yielding 2-alkoxyflavans.Flavonols react with N-bromosuccinimide and alcohols to give bromine-free hemiacetals, the known 2,3-dialkoxy-3-hydroxyflavanones.
