A new series of N-(1H-tetrazol-5-yl)-6-phenyl-2-pyridinecarboxamides was prepared to determine the effects of substituents on the benzene and pyridine rings on antiallergic activity in the rat passive cutaneous anaphylaxis (PCA) assay after oral administration. One member of this series, N-(1H-tetrazol-5-yl)-4-methyl-6-[4-(methylamino)-phenyl]-2- pyridinecarboxamide (231), has an ED50 value of 0.8 mg/kg po and is 85 times more potent than disodium cromoglycate (DSCG) on intravenous administration. Further evaluation of 231 as a clinically useful antiallergic agent is in progress.
Nitroarenes as the Nitrogen Source in Intermolecular Palladium‐Catalyzed Aryl C–H Bond Aminocarbonylation Reactions
作者:Fei Zhou、Duo‐Sheng Wang、Xinyu Guan、Tom G. Driver
DOI:10.1002/anie.201612324
日期:2017.4.10
aminocarbonylation of aryl and heteroaryl sp2 C−H bonds using nitroarenes as the nitrogen source was achieved using Mo(CO)6 as the reductant and origin of the CO. This intermolecular C−H bond functionalization does not requires any exogenous ligand to be added, and our mechanism experiments indicate that the palladacycle catalyst serves two roles in the aminocarbonylation reaction: reduce the nitroarene
Sulfonated N-Heterocyclic Carbenes for Pd-Catalyzed Sonogashira and Suzuki-Miyaura Coupling in Aqueous Solvents
作者:Sutapa Roy、Herbert Plenio
DOI:10.1002/adsc.200900886
日期:——
of the respective disulfonated N‐heterocyclic carbene (NHC) precursors in reasonable yields (46–77%). Water‐soluble palladium catalyst complexes, in situ obtained from the respective sulfonated imidazolinium salt, sodium tetrachloropalladate (Na2PdCl4) and potassium hydroxide (KOH) in water, were successfully applied in the copper‐free Sonogashiracoupling reaction in isopropyl alcohol/water mixtures
Herein we present a Pd-catalyzeddirectC–H hydroxylation of 2-arylpyridines using molecular oxygen (O2) as the sole oxidant. The key aspects of the method include: (a) the activation of molecular oxygen with a nontoxic and inexpensive aldehyde; (b) an efficient association of the in situ-generated acyl peroxo radical with palladium catalysis; and (c) convenient operating conditions. On the basis of
本文中,我们介绍了使用分子氧(O 2)作为唯一氧化剂的Pd催化2-芳基吡啶的直接C–H羟基化反应。该方法的关键方面包括:(a)用无毒且廉价的醛活化分子氧;(b)原位产生的酰基过氧自由基与钯催化的有效结合;(c)方便的操作条件。基于一系列对照实验中获得的结果,涉及Pd II / Pd IV催化循环的转化。此外,该方法可容易地以良好的分离产率获得广泛范围的取代的2-(吡啶-2-基)苯酚。
P,N,N-Pincer nickel-catalyzed cross-coupling of aryl fluorides and chlorides
作者:Dan Wu、Zhong-Xia Wang
DOI:10.1039/c4ob01041h
日期:——
were synthesized and their catalysis toward the Kumada or Negishi cross-coupling reaction of aryl fluorides and chlorides was evaluated. Complex 3a effectively catalyzes the cross-coupling of (hetero)aryl fluorides with aryl Grignard reagents at room temperature. Complex 3a also catalyzes the cross-coupling of (hetero)arylchlorides and arylzinc reagents at 80 °C with low catalyst loadings and good
P,N,N-镍镍配合物[Ni(Cl)N(2-R 2 PC 6 H 4)(2'-Me 2 NC 6 H 4)}](R = Ph,3a ; R = Pr i,合成了3b; R = Cy,3c),并评估了它们对芳基氟化物和氯化物的Kumada或Negishi交叉偶联反应的催化作用。在室温下,配合物3a有效催化(杂)芳基氟化物与芳基格氏试剂的交叉偶联。复杂3a 它还在低催化剂负载和良好的官能团相容性下,于80°C催化(杂)芳基氯和芳基锌试剂的交叉偶联。
Streamlined Synthesis of C(sp<sup>3</sup>)-Rich <i>N</i>-Heterospirocycles Enabled by Visible-Light-Mediated Photocatalysis
作者:Nils J. Flodén、Aaron Trowbridge、Darren Willcox、Scarlett M. Walton、Yongjoon Kim、Matthew J. Gaunt
DOI:10.1021/jacs.9b03372
日期:2019.5.29
We report a general visible-light-mediated strategy that enables the construction of complex C(sp3)-rich N-heterospirocycles from feedstock aliphatic ketones and aldehydes with a broad selection of alkene-containing secondary amines. Key to the success of this approach was the utilization of a highly reducing Ir-photocatalyst and orchestration of the intrinsic reactivities of 1,4-cyclohexadiene and