Metal-Free, Regioselective, Dehydrogenative Cross-Coupling between Formamides/Aldehydes and Coumarins by C-H Functionalization
作者:Mohit Gupta、Prashant Kumar、Vijay Bahadur、Krishan Kumar、Virinder S. Parmar、Brajendra K. Singh
DOI:10.1002/ejoc.201701764
日期:2018.2.21
A general methodology for the regioselective C‐3 functionalization of coumarins and azacoumarins by using formamides and aldehydes has been achieved in a single step with tert‐butyl peroxybenzoate as a radical initiator. This methodology provides a convenient and cost‐effective route to the products under metal‐free conditions with excellent regioselectivity and wide substrate scope.
Potassium Fluoride Promoted Reaction of 3-Acylsubsti-Tuted 2H-1-Benzopyran-2-Ones with Acid Anhydrides. An Improved Method for the Synthesis of 4-(2-Oxoalkyl)-2H-Chroman-2-Ones. Part III<sup>1</sup>
作者:Anka Bojilova、Nestor A. Rodics、Rozitsa Nikolova、Christo Ivanov
DOI:10.1080/00397919208019275
日期:1992.3
Abstract The reaction of 3-acylsubstituted 2H-1-benzo-pyran-2-ones 1, 5 and 11a-c with acid anhydrides in the presence of potassiumfluoride (KF)/molecular sieves 4A gives the 4-(2-oxoalkyl)-2-oxochromans 2, 6 and 12a-c as the main products. Also the 3-carboxylic acid derivatives, such as esters and N,N-dialkylamides, of 2H-1-benzopyran-2-one (11d-g) react with isobutyric acid anhydride in the presence