Hydrocarbon Activation Biphenyl Compounds Were Synthesized

Functionalized biphenyls, terphenyls and quaterphenyls, as the structural motifs innatural products, are the important part of organic electronics, pharmaceuticals andagrochemicals. C-H activation reactions were widely applied to synthesize biphenylcompounds due to the mild conditions and preclusion of pre-activation for substance.Acylamino as directing group, a palladium catalyzed C-H activation reaction wasstudied. Two synthesis approaches of biphenyls and multiphenyls were developed asnew reaction system. A synthetic route of N-biphenylamide antibiotics was alsodeveloped.Firstly, a new system of palladium catalyzed C-H functionalization reaction wasdeveloped. The reaction conditions including amounts of catalysts, bases, oxidants,solvents and atmosphere were investigated strictly. Twenty compounds of biaryls weresynthesized with the optimized reaction conditions. The less loading of the catalyst andenvironmental solvent were used in the mild reaction conditions.Secondly, the reaction system of preparing multiphenyls was developed byconsecutive reaction of Suzuki coupling reaction and C-H activation reaction in one-pot.Optimized reaction conditions were obtained by screening of ligands and temperature.Twenty-three multiphenyls were synthesized by the optimized condition. In the one-potreaction system of preparing multiphenyls, reaction steps were simplified and wasteswere reduced, so it has a better application value.Finally, five antimicrobial drugs of N-biphenylacetamide have been synthesizedvia the developed Pd-catalyzed directed C-H functionalization to N-biphenyl acetanilideand subsequent hydrolysis and acylation reaction. Compared with conventional reactionapproach, the pre-activation of substances was precluded. Additional, derivatives ofN-biphenylacetamide are easily synthesized due to halo atoms containing in thesestructures.