An efficient phosphine-free direct C–Harylation of thiophenes at the α-position has been developed at low catalyst loading of bis(alkoxo)palladium complex (Cat.I, 0.1–0.2 mol %). The developed synthetic method can be applied to the synthesis of α-aryl/heteroaryl thiophenes from aryl or heteroaryl bromides in good to excellent yields and is compatible with the substrates bearing electron-donating or
Palladium-Catalyzed Direct Arylation of Heteroaromatic Compounds: Improved Conditions Utilizing Controlled Microwave Heating
作者:Mostafa Baghbanzadeh、Christian Pilger、C. Oliver Kappe
DOI:10.1021/jo201516v
日期:2011.10.7
A versatile and rapid microwave-assisted procedure for the palladium-catalyzed direct arylation of heterocycles by arylbromides and heteroarylbromides is described. This novel protocol features short coupling times (10–60 min) and low catalyst loadings (1 mol %) and allows the successful arylation of previously unreactive heterocyclic substrates.
The direct C-H heteroarylation of thiophenes, promoted by rigid α-diimine palladium complexes is described. This approach exhibits broad substrate scopes with functional group tolerant, and proceeds with the formation of regioselective products.