Rhodium-Catalyzed Functionalization Of 2-Phenylindole With Diazo Compounds

In recent years,transition-metal-catalyzed C-H bond functionalization has received considerable attention and intensive study.Indoles are commonly occurring structural skeletons found in numerous natural products,biologically active compounds,and pharmaceuticals.Accordingly,efficient development of functionalized indoles has attracted more and more chemists.In this thesis,we reported facile and mild Rh?III?-catalyzed NH-indole-directed functionalizations of 2-arylindoles with diazo compounds.First,we have disclosed a mild rhodium-catalyzed ortho-selective C-H functionalization of 2-arylindoles with diazo compounds via NH-indole-directed C-H bond cleavage.The reaction is employed the conditions of 2-phenylindole?1 equiv.?,diazo compounds?2.1 equiv.?,[Cp*RhCl₂]₂?2.5 mol%?,silver acetate?15 mol%?in ethyl acetate at 60°C for 4 h.The catalytic reaction features mild reaction conditions,broad substrate scope and good functional group tolerability.Next,we have also developed a catalytic system for the C3-C_ortho cyclization of2-aryl-3-formylindoles or 2-?2-phenyl-1H-indol-3-yl?acetaldehydes with diazo compounds.The reaction,carried out in the presence of 2.5 mol%of[Cp*RhCl₂]₂ and 15mol%of silver acetate,provides diversified 6,11-dihydro-5H-benzo[a]carbazol-6-ols or5,6,7,12-tetrahydrobenzo[6,7]cyclohepta[1,2-b]indol-7-ols in reasonable to good yields.