proceeding through dual C–H bond cleavage and dual C–C bond formation. The procedure tolerates a series of functional groups, such as methyl, fluoro, chloro, acetyl, methoxy carbonyl, cyano, and trifluoromethyl. Thus, it represents a facile pathway leading to 6-substitutedphenanthridine derivatives. The addition of radical to the isonitrile followed by a radical aromatic cyclization is involved in this
benzoyl peroxide promoted cyclization reaction of 2-isocyanobiphenyls with carbon tetrachloride is developed. A radical pathway is proposed and evidenced for the reaction mechanism. This reaction tolerates a wide range of functional groups and the resulting 6-trichloromethylphenanthridines can be utilized as a useful synthetic precursor for corresponding 6-substituted phenanthridines.
Combination of PhI(OAc)<sub>2</sub> and 2-Nitropropane as the Source of Methyl Radical in Room-Temperature Metal-Free Oxidative Decarboxylation/Cyclization: Construction of 6-Methyl Phenanthridines and 1-Methyl Isoquinolines
A room-temperature metal-free method for generating highly unstable methyl radical was realized from the combination of PhI(OAc)2 and 2-nitropropane, which provides an efficient approach to methylated phenanthridines and isoquinolines. The strategy was also extended to the generation of other alkyl radicals and a concise synthesis of Roxadustat.
cyclization phosphorylation of isocyanides and Csp2−H phosphorylation. Under visible-light irradiation, a series of phosphorus-substituted phenanthridines, benzothiazoles, isoquinolines, and common heteroaromatics were obtained in good to excellent yields without any aid of electrolysis, metal reductants, or oxidants, and with only H2 or CH4 as byproduct.