A novel Pd(OAc)2-NFSI-TFA system was developed for the highly selective ortho-monofluorination directed by diverse aryl-N-heterocyclic directing groups e.g., quinoxaline, pyrazole, benzo[d]oxazole, and pyrazine derivatives. A Pd(II/IV) catalytic cycle was proposed based on the ESI-MS/MS studies.
Direct Zincation of Functionalized Aromatics and Heterocycles by Using a Magnesium Base in the Presence of ZnCl<sub>2</sub>
作者:Zhibing Dong、Giuliano C. Clososki、Stefan H. Wunderlich、Andreas Unsinn、Jinshan Li、Paul Knochel
DOI:10.1002/chem.200801558
日期:2009.1.2
A wide range of polyfunctional aryl and heteroaryl zinc reagents were efficiently prepared in THF by using (TMP)2Mg⋅2 LiCl (TMP=2,2,6,6‐tetramethylpiperamidyl) in the presence of ZnCl2. The possible pathways of this metalation procedure as well as possible reactive intermediates are discussed. This experimental protocol expands the tolerance of functional groups and allows an efficient zincation of
Compounds having the structure of Formula Ia, including pharmaceutically acceptable salts of the compounds, are CETP inhibitors and may be useful for raising HDL-cholesterol, reducing LDL-cholesterol, and for treating or preventing atherosclerosis.
Sulfur‐Catalyzed Oxidative Condensation of Aryl Alkyl Ketones with
<i>o</i>
‐Phenylenediamines: Access to Quinoxalines
作者:Le Anh Nguyen、Thi Thu Tram Nguyen、Quoc Anh Ngo、Thanh Binh Nguyen
DOI:10.1002/adsc.202200527
日期:2022.8.16
While elemental sulfur has been largely used as oxidant or sulfurating agent, its role as a catalyst has not been developed. We report here its catalytic activity in the oxidative condensation of o-phenylenediamines with acetophenones in DMSO to provide quinoxalines. The method was also extended to α-tetralones, propiophenones (R=Me) as well as higher homologues (R=Et, n-Pr) in place of acetophenones
Dearomative bis-functionalization of quinoxalines and bis-<i>N</i>-arylation of (benz)imidazoles <i>via</i> Cu(<scp>ii</scp>)-mediated addition of boronic acids
作者:Tamanna Khandelia、Subhendu Ghosh、Bhisma K. Patel
DOI:10.1039/d2cc06399a
日期:——
A Cu(OTf)2-mediated regioselective dearomative aryl-hydroxylation across the C(sp2)N bond of 2-aryl quinoxalines and bis-N-arylation of (benz)imidazoles were developed using aryl boronic acids.