Initially we examined the homocoupling reaction of 4??iodoanisole as a model in various solvent systems using Pd(PPh 3 ) 4 (4 mol%) and indium (1 equiv.) under the conditions mentioned in Table 1, and DMF was identified to be the best solvent in yield and reaction time. The reaction in DMF was complete in 3 h to give a biphenyl in 81.1% isolated yield (entry 6). The reactions in THF or methanol at reflux did not proceed at all (entries 1 and 4) and those in ...
[Yamamoto; Harada; Okamoto; Chikamatsu; Nakazaki; Kai; Nakao; Tanaka; Kasai Journal of the American Chemical Society, 1988 , vol. 110, # 11 p. 3578 - 3584]