A convenient, effective and mild protocol has been developed for the palladium-catalyzed ligand-free Suzuki reaction of aryl bromides with arylboronic acids in aqueous N,N-dimethylformamide (DMF) in the presence of K 2 CO 3 and a catalytic amount of PdCl 2 in air at room temperature. It is noteworthy that the volume ratio of water-DMF and base play important roles in the reaction, and various functional groups are tolerated under the optimized conditions. Furthermore, this protocol could be extended to the cross-couplings of nitrogen-based heteroaryl halides with arylboronic acids in moderate to excellent yields.

A simple, highly efficient and phosphine-free protocol for the Sonogashira coupling of aryl iodides with terminal alkynes has been developed using Pd 2 (dba) 3 (dba=dibenzylideneacetone) as the catalyst under aqueous, copper-free and aerobic conditions. The coupling of aryl iodides with aromatic terminal alkynes provided good to excellent yields and moderate to good yields were achieved using aliphatic terminal alkynes as one of the coupling partners. Aqueous ethanol as solvent is economical and environmentally benign in accordance with the concept of green chemistry.

DMF. -The convenient and mild protocol for the title synthesis of the compounds (III), (VI), and (VIII) under aerobic conditions is more effective than under a nitrogen atmosphere. -(LIU*, C.; NI, Q.; BAO, F.; QIU, J.; Green Chem. 13 (2011) 5, 1260-1266, http://dx.doi.org/10.1039/c0gc00176g ; State Key Lab. Fine Chem., Dalian Univ.