Oxidative hydroxylation of arylboronic acids to phenols catalyzed by copper nanoparticles ellagic acid composite
摘要:
Copper nanoparticles (Cu NPs) were prepared by in situ reduction of CuSO4 center dot 5H(2)O using ellagic acid (EA) as the reducing agent as well as stabilizer and its catalytic activity is tested in the oxidative hydroxylation of phenylboronic acids to phenol without any added base or ligand. The synthesized Cu NPs-EA composite was characterized by UV-Vis., FT-IR, powder XRD and HRTEM analyses. The average particle size of Cu NPs is found to be in the range of 20-25 nm as evident from HRTEM and copper content is estimated to be 3.18 wt%. EA acts both as a reducing agent as well as a stabilizer for the in situ formation of Cu NPs. A small portion of Cu NPs is also found to undergo aerobic oxidation to give Cu2O NPs which does not take part in the reactions. A series of arylboronic acids are converted to the corresponding phenols in high yields at short reaction time under milder reaction conditions. It is also observed that Cu NPs-EA composite can be reused at least four times with a significant decrease in the yield. (C) 2014 Elsevier B.V. All rights reserved.
10a-Azalide compound crosslinked at 10a- and 12-positions
申请人:Taisho Pharmaceutical Co., Ltd.
公开号:US08293715B2
公开(公告)日:2012-10-23
A novel 10a-azalide compound crosslinked at the 10a- and 12-positions, which is represented by the following formula, and is effective on even Hemophilus influenzae, or erythromycin resistant bacteria (e.g., resistant pneumococci and streptococci).
10A-AZALIDE COMPOUND CROSSLINKED AT 10A- AND 12-POSITIONS
申请人:Sugimoto Tomohiro
公开号:US20110237784A1
公开(公告)日:2011-09-29
A novel 10a-azalide compound crosslinked at the 10a- and 12-positions, which is represented by the following formula, and is effective on even
Hemophilus influenzae
, or erythromycin resistant bacteria (e.g., resistant pneumococci and streptococci).
10A-AZALIDE COMPOUND CROSSLINKED AT POSITION-10A AND POSITION-12
申请人:Taisho Pharmaceutical Co. Ltd.
公开号:EP2177526A1
公开(公告)日:2010-04-21
A novel 10a-azalide compound crosslinked at the 10a- and 12-positions, which is represented by the following formula, and is effective on even Hemophilus influenzae, or erythromycin resistant bacteria (e.g., resistant pneumococci and streptococci).