Proline Catalyzes Direct C?H Arylations of Unactivated Arenes

摘要

Several amino acids were tested to catalyze thentransition-metal-free direct C−H arylation of unactivatednbenzene derivatives. Among them, proline was found to be annexcellent catalyst for the cross-coupling between aryl halides andnunactivated arenes. The reaction presumably involves an arylnradical anion as the intermediate based on several experiments.nThe reaction using this catalyst system offers an option towardnestablishing an environmentally benign and cost-effective route to biaryls.