2-Pyridinyl-3-(4-methylsulfonyl)phenylpyridines: Selective and orally active cyclooxygenase-2 inhibitors
摘要:
A series of novel 2-pyridinyl-3-(4-methylsulfonyl)phenylpyridines has been synthesized and evaluated with respect to their ability to inhibit the isozymes of cyclooxygenase, COX-I, and COX-2. Optimum COX-2 activity is observed by introduction of a substituent at C5 of the central pyridine. 5-Chloro-3-(4-methylsulfonyl)phenyl-2-(2-methyl-5-pyridinyl)pyridine 33 was identified as the optimum compound in this series. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.
styrene and vinylarenes, the aryl and vinyl groups routinely insert at the β position. However, selective insertion at the αposition has been very rare. Herein, we provide a missing piece in the palette of Heck reaction, which gave >20:1 αselectivity. The key to our success is a new ferrocene 1,1′‐bisphosphane (dnpf) that carries 1‐naphthyl groups. Our mechanistic studies revealed that the high α selectivity
General Chemoselective Suzuki–Miyaura Coupling of Polyhalogenated Aryl Triflates Enabled by an Alkyl-Heteroaryl-Based Phosphine Ligand
作者:Chau Ming So、On Ying Yuen、Shan Shan Ng、Zicong Chen
DOI:10.1021/acscatal.1c02146
日期:2021.7.2
describes a general chemoselective Suzuki–Miyauracoupling of polyhalogenated aryl triflates with the reactivity order of C–Cl > C–OTf using a Pd/L33 catalyst. The methine hydrogen and the steric hindrance offered by the alkyl bottom ring of L33 were found to be key factors in reactivity and chemoselectivity. With the Pd/L33 catalyst, a wide range of polyhalogenated (hetero)aryl triflates, which were independent
Palladium‐Catalyzed Directed Atroposelective C−H Iodination to Synthesize Axial Chiral Biaryl N‐Oxides via Enantioselective Desymmetrization Strategy
作者:Linxi Yao、Alemayehu Gashaw Woldegiorgis、Shaoying Huang、Yongtao Wang、Xufeng Lin
DOI:10.1002/chem.202203051
日期:2023.1.24
Pd(II) coordinated by N-benzoyl-l-phenylalanine has been identified as a highly enantioselective catalyst for atroposelectiveC−Hiodination at room temperature via desymmerization strategy providing nearly enantiopure samples of a diverse range axiallychiralbiaryl N-oxides. Mechanistic investigation disclosed the factors that lead to high reactivity and excellent enantiocontrol.
由N -苯甲酰基 - l -苯丙氨酸配位的 Pd(II)已被确定为一种高度对映选择性催化剂,可在室温下通过去对称化策略进行阻转选择性 C-H 碘化,提供各种轴向手性联芳基 N -氧化物的近对映体纯样品。机理研究揭示了导致高反应性和出色对映体控制的因素。
A variety of diversely substituted aryl triflate esters were efficiently deprotected to the parent phenols by exposure to cesium carbonate in toluene. This procedure proved highly compatible with existing functional groups. (C) 2013 Elsevier Ltd. All rights reserved.