Manganese dioxide mediated oxidativecleavage of 1,3-disubstituted benzo[c]furans in dichloromethane at room temperature gave good yields of 1,2-di(het)aroylbenzenes.
Oxidative Ring Opening of 1,3-Diarylbenzo[c]heterocycles Using m-CPBA: Preparation of 1,2-Diaroylbenzenes
作者:Meganathan Nandakumar、Ramakrishnan Sivasakthikumaran、Arasambattu K. Mohanakrishnan
DOI:10.1002/ejoc.201200311
日期:2012.7
An unprecedented oxidative cleavage of benzo[c]heterocyclesusingm-CPBA is reported. The reaction of 1,3-diaryl benzo[c]heterocycles with m-CPBA (meta-chloroperoxybenzoic acid) at room temperature for 5 min led to the formation of 1,2-diaroylbenzenes in good to excellent yields.
Regioselective Annulation of Unsymmetrical 1,2-Phenylenebis(diaryl/diheteroarylmethanol): A Facile Synthesis of Anthracene, Tetracene, and Naphtho[<i>b</i>]thiophene Analogues
作者:Ramakrishnan Sivasakthikumaran、Settu Muhammad Rafiq、Elumalai Sankar、J. Arul Clement、Arasambattu K. Mohanakrishnan
DOI:10.1002/ejoc.201501087
日期:2015.12
A systematic study on the regioselective cyclization of benzene- and naphthalene-based unsymmetrical diols with HBr (33 %) in acetic acid at room temperature led to the formation of annulation products. By using this method, synthesis of a wide variety of anthracene, tetracene and naphtho[b]thiopheneanalogues was achieved in good to excellent yields. By employing HBr (33 %) in acetic acid as a catalyst
Copper-Catalyzed Benzylic C−H Oxygenation under an Oxygen Atmosphere via <i>N</i>-H Imines as an Intramolecular Directing Group
作者:Line Zhang、Gim Yean Ang、Shunsuke Chiba
DOI:10.1021/ol200425c
日期:2011.4.1
Copper-catalyzed benzylic C-H oxygenation under an oxygen atmosphere was developed starting from carbonitriles and Grignard reagents via N-H imine intermediates. The present process is characterized by the following two-step sequence in a one-pot manner: (1) addition of Grignard reagents to carbonitriles to form N-H imines and (2) benzylic C-H oxygenation (C=O bond formation) triggered by 1,5-hydrogen atom transfer with transient iminyl copper species.