Efficient palladium(II)-catalyzed homocoupling of thiazole-4-carboxylic or oxazole-4-carboxylic derivatives
摘要:
An efficient Pd(OAc)(2)-catalyzed homocoupling of thiazole-4-carboxylic or oxazole-4-carboxylic derivatives is described. It represents a facile and practical methodology to prepare bis-5,5'-thiazole (oxazole)-4,4'-dicarboxylic derivatives in good to excellent yields. This protocol tolerates a series of substitutions on the thiazole (oxazole) rings, including alkyl, carbonyl, and electron-withdrawing/donating group substituted phenyl groups. (C) 2011 Elsevier Ltd. All rights reserved.
Cobalt-Catalyzed Cross-Dehydrogenative C(sp<sup>2</sup>
)−C(sp<sup>3</sup>
) Coupling of Oxazole/Thiazole with Ether or Cycloalkane
作者:Xiaojiao Wang、Bowen Lei、Lifang Ma、Lisi Zhu、Xinyue Zhang、Hao Zuo、Dailin Zhuang、Ziyuan Li
DOI:10.1002/asia.201701258
日期:2017.11.2
Direct C5‐alkylation of oxazole/thiazole with ether or cycloalkane has been achieved through a cobalt‐catalyzed cross‐dehydrogenative coupling (CDC) process in moderate to good yields. This transformation represents the first C(sp2)−C(sp3) cross‐coupling at the C5‐position of the oxazole/thiazole via double C−H bond cleavages. Various functional groups on oxazole/thiazole substrates, as well as water
Purple acid phosphatase inhibitors as leads for osteoporosis chemotherapeutics
作者:Waleed M. Hussein、Daniel Feder、Gerhard Schenk、Luke W. Guddat、Ross P. McGeary
DOI:10.1016/j.ejmech.2018.08.004
日期:2018.9
obtaining the human enzyme, the corresponding enzymes from red kidney bean and pig have been used previously to develop specific PAP inhibitors. Here, existing lead compounds were further elaborated to create a series of inhibitors with Ki values as low as ∼30 μM. The inhibition constants of these compounds were of comparable magnitude for pig and red kidney bean PAPs, indicating that relevant binding interactions
作者:Anna C. Dawsey、Vincent Li、Kimberly C. Hamilton、Jianmei Wang、Travis J. Williams
DOI:10.1039/c2dt00025c
日期:——
We report herein convenient, aerobic conditions for the oxidation of thiazolines to thiazoles and data regarding the oxidation mechanism. These reactions feature operationally simple and environmentally benign conditions and proceed in good yield to afford the corresponding azoles, thus enabling the inexpensive preparation of valuable molecular building blocks. Incorporation of a novel diimine-ligated copper catalyst, [(MesDABMe)CuII(OH2)3]2+ [−OTf]2, provides increased reaction efficiency in many cases. In other cases copper-free conditions involving a stoichiometric quantity of base affords superior results.
Azolines are oxidized in the presence of a copper-containing catalyst to azoles in the presence of molecular oxygen. A synthetic scheme converting azolines azoles is also provided.
在含有铜催化剂的情况下,吡唑烯被氧化为吡唑,同时存在分子氧。还提供了将吡唑烯转化为吡唑的合成方案。
Iron-catalyzed C(5)−H Imidation of Azole with <i>N</i>
-Fluorobenzenesulfonimide
作者:Xiaojiao Wang、Bowen Lei、Lifang Ma、Huixuan Jiao、Wenhua Xing、Jiaming Chen、Ziyuan Li
DOI:10.1002/adsc.201701124
日期:2017.12.19
An iron(II)‐catalyzed direct imidation of oxazole and thiazole with N‐fluorobenzenesulfonimide (NFSI) through C(5)−H bond cleavage is disclosed, providing C5‐imidated azoles in moderate to excellent yields with broad substrate scope. This reaction represents the first iron‐catalyzed C−Himidation of arene where NFSI serves as the imidation reagent, and potentially constitutes an efficient access to