Pd/Pivalic Acid Mediated Direct Arylation of 2-Pyrones and Related Heterocycles
作者:Leticia M. Pardo、Aisling M. Prendergast、Marie-T. Nolan、Eoin Ó Muimhneacháin、Gerard P. McGlacken
DOI:10.1002/ejoc.201500262
日期:2015.6
Directarylation represents a favourable alternative to traditional cross-coupling reactions and has found widespread use with simple aryls and robust heterocycles. Herein a directarylation protocol has been optimised and applied to more delicate, privileged biological motifs. The intramolecular directarylation of 2-pyrones, 2-coumarins, 2-pyridones and 2-quinolones occurs in very good to excellent
Pd-catalysed intramolecular regioselective arylation of 2-pyrones, pyridones, coumarins and quinolones by C–H bond functionalization
作者:Marie-Therese Nolan、Joshua T.W. Bray、Kevin Eccles、Man Sing Cheung、Zhenyang Lin、Simon E. Lawrence、Adrian C. Whitwood、Ian J.S. Fairlamb、Gerard P. McGlacken
DOI:10.1016/j.tet.2014.04.029
日期:2014.10
The intramolecular arylation of 2-pyrones, 2-pyridones, coumarins and quinolones is reported using Pd-II precatalyst sources without added phosphine ligands. The excellent yields and convenient reagents enables the formation of various analogues containing these moieties, and access to potential biologically active candidates. Stoichiometric studies were carried out to provide an insight into the oxidation addition step. A switch in regioselectivity, together with a hydrodebromination process, was observed in the case of a 3-bromo-2-pyrone. (C) 2014 Elsevier Ltd. All rights reserved.