Polymer-supported gadolinium triflate as a convenient and efficient Lewis acid catalyst for acetylation of alcohols and phenols
作者:Hyo-Jin Yoon、Sang-Myung Lee、Jong-Ho Kim、Hong-Jun Cho、Jung-Woo Choi、Sang-Hyeup Lee、Yoon-Sik Lee
DOI:10.1016/j.tetlet.2008.03.005
日期:2008.5
(CMPS-IM-Gd) catalyst was prepared from chloromethyl polystyrene (CMPS) resin using a simple and convenient procedure. This polymeric catalyst was used as an efficient Lewisacidcatalyst for the acetylation of various alcohols and phenols with acetic anhydride, affording high yields under mild conditions. The reaction was completed in a short period of time with small amounts of the catalyst. The catalyst
Rh-Catalyzed Synthesis of Coumarin Derivatives from Phenolic Acetates and Acrylates <i>via</i> C–H Bond Activation
作者:Sunita K. Gadakh、Soumen Dey、Arumugam Sudalai
DOI:10.1021/acs.joc.5b01713
日期:2015.11.20
An efficient annulation strategy involving the reaction of phenolic acetates with acrylates in the presence of [Rh2(OAc)4] as catalyst and formic acid as reducing agent, leading to the high yield synthesis of coumarin derivatives, has been developed. The addition of NaOAc as a base increased the yield of the products. The reaction is quite successful for both electron-rich as well as electron-deficient
The present invention relates to a phenylalanine derivative of Formula (I) wherein X
1
is a halogen atom, X
2
is a halogen atom, Q is a CH
2
R— is a carboxyl group which may be esterified; or a pharmaceutically acceptable salt thereof.
PhI(OAc)2-mediated oxidative trifluoromethylation of arenes with CF3SiMe3 under metal-free conditions
作者:Xinyue Wu、Lingling Chu、Feng-Ling Qing
DOI:10.1016/j.tetlet.2012.11.011
日期:2013.1
A PhI(OAc)2-mediated oxidative trifluoromethylation of arenes with CF3SiMe3 under metal-free conditions has been described. This protocol precludes the need of substrate pre-functionalization and metal catalysts, enabling a direct access to a series of trifluoromethylated arenes and heterocycles containing common functional groups in moderate and good yields.
The octaketide cytosporone B has been synthesized in six steps using 1,3,5-trihydroxybenzene as a starting material via aryne insertion reaction into a carbon–carbon σ-bond.