Synthesis of 2,3-Disubstituted o-Terphenyls

The versatile Suzuki reaction [31] was combined with the sequence leading to biphenylylpalladium iodide complexes to obtain aryl coupling [52]. Once again the best results were obtained with a moderately bulky o-substituent such as 

The reaction is also compatible with the presence of an ortho substituent in the arylboronic acid, while arylboronic acid with two ortho substituents was not reactive. By-products from aryl scrambling and biaryl from homocoupling were not found. The reaction proceeds as previously indicated up to the formation of the biphenylylpalladium species and is terminated by the Suzuki coupling as in Eq. 45. 

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