查看更多>>摘要：A light-driven, catalyst-and additive-free photoenolization/nucleophilic addition reaction for the synthesis of 3-benzyl-3-hydroxyindolin-2-ones is presented. In this reaction, 2-methylbenzophenones undergo light-induced enolization process to afford hydroxy-o-quinodimethanes (hydroxy-o-QDMs), which are then immediately captured by the electrophilic isatins. The reaction utilizes green and clean light energy to realize the C-H activation of the inert benzyl position of 2-methylbenzophenones. This method tolerates a wide scope of substrates and provides concise access to a series of novel 3-benzyl3-hydroxyindolin-2-ones with 60-99% yields.(c) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：We report herein the synthesis of functionalized styrenes via palladium-catalyzed Suzuki-Miyaura cross-coupling reaction between aryl ketone derivatives and potassium vinyltrifluoroborate. The employment of pyridine-oxazoline ligand was the key to the cleavage of unstrained C-C bond. A variety of functional groups and biologically important moleculars were well tolerated. The orthogonal Suzuki-Miyaura cou-pling demonstrated the synthetic practicability.(c) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：A novel pterocarpan, named phaseollin A (1) was isolated from Lima bean (the seeds of Phaseolus lunatus L.). The structure of 1 was elucidated by the extensive spectroscopic analysis (1D and 2D NMR, HR-ESIMS) as well as the experimental and calculated ECD data analysis. Compound 1 showed moderate activity of inhibiting NO production on lipopolysaccharide (LPS)-induced RAW264.7 cells with IC50 value of 37.13 & nbsp;+/- 2.58 lM.(C 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：A convenient and novel route for the stereoselective synthesis of 3,5-Di-O-benzoyl-2-deoxy-2-chloro-2-C-methyl-D-ribono-c-lactone 5a and its analogues is developed by an Evans-Aldol reaction in the presence of TiCl4. Starting from 2-chloropropionyl chloride, 5a is efficiently and regioselectively produced on a kilogram scale in an overall yield of 32% with an HPLC purity of 98% by area. In addition, this approach allowed an efficient synthesis of 3,5-Di-O-benzoyl-2-deoxy-2-fluoro-2-C-methyl-D-ribono-c- lactone 5b in a total 20% yield. (C)& nbsp;2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：We report a cesium bicarbonate-mediated alkylation of 2,4-dihydroxybenzyaldehyde and 2,4-dihydroxyacetophenone to generate 4-alkylated products in acetonitrile at 80 degrees C with excellent regioselectivity, up to 95% isolated yields, and broad substrate scope.(c) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：Herein, the synthesis of 6,7-benzene-fused tropane derivatives from isoindoline-aminal hybrid compound has been reported. In the present synthetic study, ring-closing metathesis (RCM) was employed to construct the 6,7-benzene-fused tropene skeleton. To obtain the desired cis-1-allyl-3-stylylisoindoline precursor for the RCM reaction, the diastereoselective aza-Hosomi-Sakurai allylation and functional group transformations of isoindoline-aminal hybrid compound were performed. Using the synthesized 6,7-benzene-fused tropene derivative as a versatile precursor, synthesis of several 6,7-benzene-fused tropane derivatives was demonstrated by the transformations of the internal alkene moiety.(c) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：A squaramide organocatalyst efficiently promoted the asymmetric Friedel-Crafts alkylation of oc,6-unsat-urated trifluoromethyl ketones with aromatic alcohols in a one-pot procedure, affording corresponding 6trifluoromethyl-substituted 7,8-dihydrochromen-6-ol derivatives (up to 94% yield, 74% ee). (C)& nbsp;& nbsp;2022 Elsevier Ltd. All rights reserved.
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