Synthesis of azafluorenones and related compounds using deprotocupration–aroylation followed by intramolecular direct arylation
摘要:
The efficiency of the deprotocupration-aroylation of 2-chloropyridine using lithiocuprates prepared from CuX (X=Cl, Br) and LiTMP (TMP=2,2,6,6-tetramethylpiperidido, 2 equiv) was investigated. CuCl was identified as a more suitable copper source than CuBr for this purpose. Different diaryl ketones bearing a halogen at the 2 position of one of the aryl groups were synthesized in this way from azines and thiophenes. These were then involved in palladium-catalyzed ring closure: substrates underwent expected CH-activation-type arylation to afford fluorenone-type compounds, and were also subjected to cyclization reactions leading to xanthones, notably in the presence of oxygen-containing substituents or reagents. (C) 2013 The Authors. Published by Elsevier Ltd. All rights reserved.
Azine and Diazine Functionalization Using 2,2,6,6-Tetramethylpiperidino-Based Lithium–Metal Combinations: Application to the Synthesis of 5,9-Disubstituted Pyrido[3′,2′:4,5]pyrrolo[1,2-c]pyrimidines
The synthesis of triaryl methanols was investigated by reacting different 4-metalated 2-substituted pyrimidines with diaryl ketones, the latter being generated by deprotocupration-aroylation of azine and diazine substrates. Cyclization of the triaryl methanols thus obtained afforded pyrido[3,2:4,5]pyrrolo[1,2-c]pyrimidines, which were evaluated for kinase inhibition and antiproliferative activities in melanoma cells.