Total Synthesis and Biological Evaluation of (+)- and (−)-Bisanthraquinone Antibiotic BE-43472B and Related Compounds
作者:K. C. Nicolaou、Jochen Becker、Yee Hwee Lim、Alexandre Lemire、Thomas Neubauer、Ana Montero
DOI:10.1021/ja9073694
日期:2009.10.21
respectively) and vancomycin-resistant Enterococcus faecalis (VRE). Described herein is the first totalsynthesis of both enantiomers of this bisanthraquinone antibiotic, the determination of its absolute configuration, and the biological evaluation of these and related compounds. The developed synthesis relies on a highly efficient cascade sequence involving an intermolecular Diels-Alder reaction between
Synthesis of <i>N,N</i>-Diethylbenzamides via a Nonclassical Mitsunobu Reaction
作者:J. Mason Hoffman、Justin N. Miller、Margaret E. Gardner、Danielle R. LePar、Rongson Pongdee
DOI:10.1080/00397911.2013.839796
日期:2014.4.3
Abstract The use of the Mitsunobu reaction for the synthesis of N,N-diethylbenzamides affords ortho-, meta-, and para-substituted benzamides containing both electron-donating and electron-withdrawing groups. While the preparation of numerous functional groups has been efficiently demonstrated employing the Mitsunobu reaction, our methodology represents the first application of the Mitsunobu reaction
Copper-Catalyzed Cross Dehydrogenative Coupling of<i>N</i>,<i>N</i>-Disubstituted Formamides and Phenols: A Direct Access to Carbamates
作者:Wajid Ali、Saroj K. Rout、Srimanta Guin、Anju Modi、Arghya Banerjee、Bhisma K. Patel
DOI:10.1002/adsc.201400659
日期:2015.2.9
AbstractAn efficient copper‐catalyzed protocol has been developed for the synthesis of carbamates from dialkylformamides and phenols possessing directing groups such as benzothiazole, quinoline and formyl at the ortho‐position. In this chelation assisted approach, CO bond formation takes place via a cross dehydrogenative coupling (CDC) between the formyl CH of dialkylformamide and phenolic OH in the presence of copper(II)acetate/aqueous tert‐butyl hydroperoxide. Under identical reaction conditions, salicylic acid derivatives underwent amidation with the carboxylic group rather than formamidation of the phenolic OH. The use of a cheap and environmentally benign catalyst along with the tolerance of a wide range of functional groups makes this an easy, phosgene‐free route to carbamates.magnified image
A Pauson−Khand Approach to the Hamigerans
作者:Christian E. Madu、Carl J. Lovely
DOI:10.1021/ol7018604
日期:2007.11.1
An intramolecular Pauson-Khand reaction has been used in the construction of the tricyclic core common to the hamigeran terpenes. For effective cyclization, it was necessary to tether the olefin-containing moiety to the aromatic framework to reduce its conformation mobility; this was accomplished using a silylene protecting group. Efficient construction of the aryl enyne from a salicylic acid derivative was accomplished via ortho lithiation and Sonogashira cross-coupling chemistry.