106469-28-7Relevant academic research and scientific papers
Photochemical Reactions of Aromatic Compounds. Part 44. Mechanisms for Direct Photoamination of Arenes with Ammonia and Amines in the Presence of m-Dicyanobenzene
Yasuda, Masahida,Matsuzaki, Yoriaki,Shima, Kensuke,Pac, Chyongjin
, p. 745 - 752 (2007/10/02)
Mechanistic details of the efficient photoamination of arenes (ArH) with ammonia or aliphatic primary amines (RNH2) in the presence of m-dicyanobenzene (DCNB) in 9:1 acetonitrile-water have been analysed by kinetics.The initiation of the photoamination is electron transfer from excited singlet ArH to DCNB to generate the cation radical of ArH (ArH(1+*)), to which RNH2 undergoes nucleophilic addition.The rate constant (kN) for the nucleophilic addition to the phenanthrene cation radical depends on R, varying from 3E7 dm3 mol-1 s-1 for NH3 to 8.9E8 dm3 mol-1 s-1 for ButNH2.A plot of log kN versus the Taft ?* parameter is linear with a slope of -2.1, demonstrating a substantial positive charge on RNH2 in the transition state in line with the proposed mechanism.Photoamination withMe2NH is very inefficient for naphthalene, 2-methoxynaphthalene, and phenanthrene, and is attributed to electron exchange between ArH(1+*) and Me2NH being competitive with nucleophilic addition.Anthracene is efficiently photoaminated with Me2NH but inefficiently with Et2NH.Efficient photoamination requires that the observed oxidation potential of the amines is more positive by 0.3-0.4 eV than that of ArH.
Direct Photoamination of Arenes with Ammonia and Primary Amines in the Presence of Electron Acceptors
Yasuda, Masahide,Yamashita, Toshiaki,Shima, Kensuke,Pac, Chyongjin
, p. 753 - 759 (2007/10/02)
Direct photoamination of phenanthrene, 9-methoxyphenanthrene, anthracene, naphthalene, and several substituted naphthalenes with ammonia or primary amines in the presence of m-dicyanobenzene occurs to give aminated dihydroarenes in fairly good yields. m-Dimethoxybenzene and biphenyl are photoaminated in lower yields.A suggested mechanism for the photoamination involves the nucleophilic attack of ammonia and amines on aromatic cation radicals generated by photochemical electron transfer to m-dicyanobenzene.The present photoamination is applied to direct introduction of various functionalized primary amines containing the vinyl, cyano, hydroxy, acetylamino, and ethoxycarbonyl groups.
