Synthesis of biaryls via intramolecular free radical ipso-substitution reactions
作者:Feroze Ujjainwalla、Maria Lucília E.N. da Mata、Andrew M.K. Pennell、Carmen Escolano、William B. Motherwell、Santiago Vázquez
DOI:10.1016/j.tet.2015.07.048
日期:2015.9
intramolecular freeradical [1,5]-ipso-substitution using sulfonamide and sulfonate derived tethering chains. The overall efficiency of the process is determined by appropriately positioned substituents on the aromatic acceptor ring. The extension of the process to benzylic sulfonates and their corresponding N-methylsulfonamide alternatives as substrates in potential [1,6]-ipso-substitution reactions leads
carboxylic acid bearing three cyclohexylmethyl substituents at the α‐position, namely, tri(cyclohexylmethyl)acetic acid, is demonstrated to act as an efficient ligand source in Pd‐catalyzed intramolecularC(sp2)−H and C(sp3)−H arylation reactions. The reactions proceed smoothly under mild reaction conditions, even at room temperature due to the steric bulk of the carboxylate ligands, which accelerates the