Iron-Catalyzed Construction Of C-N And C-O Bonds

Many natural products, drugs and dyes contain C-N, C-O bonds, so the transition metal-catalyzed construction of C-N, C-O bonds is an effective strategy. The iron and copper salts are applied to catalyze organic reactions for their low price and toxicity. In this dissertation, some iron catalysts and iron/copper co-catalysts were used in Ullmann N- and O-arylations, aminohalogenation of alkenes and amidation of C-H bonds, and some important results were obtained as follows:We have developed an efficient and inexpensive bimetallic catalyst FeCl₃/CuO/rac-BINOL that could greatly promote N, O-arylation of aliphatic, aryl amines and phenols, and the cross-coupling reactions were of tolerance of various functional groups, so the versatile and efficient iron/copper-co-catalyst can widely be used in the synthesis of the compounds containing the (aryl)C-N or (aryl)C-O(aryl) bond.We have developed an iron-catalyzed method for aminobromination of alkenes, the protocol uses FeCl₂ as the catalyst, NBS as the halogen source, ethyl acetate as the solvent, and the aminobrominations were efficiently performed under very mild conditions. The direct 1,2-functionalization of alkenes by inexpensive and convenient catalyst-bromine source (FeCl₂/NBS) system is of practical applications.We have developed an efficient, inexpensive and air-stable FeCl₂/NBS-mediated amidation of benzylic sp³ C-H bonds; the protocol uses FeCl₂ as the catalyst, non-explosive NBS (compared with the usual oxidants) as the oxidant, ethyl acetate as the solvent, and the amidation provided the reasonable yields under mild conditions. The reactions are insensitive to atmospheric moisture and oxygen, and neither dried solvent nor an inert atmosphere is required. The inexpensive and readily available catalyst-oxidant (FeCl₂/NBS) system is of practical applications for amidation of the unactivated C-H bonds.