An Aryl to Imidoyl Palladium Migration Process Involving Intramolecular C−H Activation
作者:Jian Zhao、Dawei Yue、Marino A. Campo、Richard C. Larock
DOI:10.1021/ja070657l
日期:2007.4.1
imidoyl palladium migration, followed by intramolecular arylation. The fluoren-9-one synthesis appears to involve both a palladium migration mechanism and a C-H activation process proceeding through an unprecedented organopalladium(IV) hydride intermediate. The results from deuterium labeling experiments are consistent with the proposed dual mechanism.
Abstract An efficient synthetic method for multi-substituted xanthones was developed. The reaction of diaryliodonium salts and salicylates was employed for the preparation of the xanthones. This method proceeded through an intermolecular etherification-acylation to give target heterocycles in good yields (up to 91%). Multi-substituted xanthones were gained by shifting the substituent of salicylates or
FeCl<sub>3</sub>and ether mediated direct intramolecular acylation of esters and their application in efficient preparation of xanthone and chromone derivatives
作者:Neng Jiang、Su-Yi Li、Sai-Sai Xie、Hequan Yao、Hongbin Sun、Xiao-Bing Wang、Ling-Yi Kong
DOI:10.1039/c4ra10174j
日期:——
The direct intramolecular acylation of esters was developed by using the combined system of FeCl3 with Cl2CHOCH3. This unique cooperative system offered a new and efficient approach to biologically important xanthone and chromone derivatives with regioselectivity. Examples were reported, and control experiments were carried out to examine the effect of the benzyl esters and Cl2CHOCH3.
QSAR equation with 13C NMR chemicalshifts as independent parameters. The key step of the synthesis is the formation of substituted 2‐phenoxybenzoic acids by Ullmann reaction followed by intramolecular Friedel‐Crafts acylation, leading to methyl‐, carboxy‐, nitro‐, cyano‐, and aminoxanthones as a test set for QSAR investigations. Spectroscopic data (1H and 13C chemicalshifts, IR, UV) of these xanthones