title: A density functional theory study of the mechanism of isomerization of 2-aryl-2H-azirines to 2,3-disubstituted indoles by FeCl2 and Rh2(O2CCF3)4.
abstract: A systematic DFT study was performed to examine the isomerization of 2-aryl-2H-azirines to 2,3-disubstituted indoles by FeCl2 and Rh2(O2CCF3)4. The results indicate that the isomerization of 2-aryl-2H-azirines mainly proceeds through a stepwise mechanism and the Rh2(O2CCF3)4 exhibits higher catalytic performance than FeCl2. Investigation of the magnetic properties suggests that the C-N bond formation step is pseudoelectrocyclization for the FeCl2-catalyzed system. The calculations show that a water-catalyzed 1,2-H shift for the FeCl2-catalyzed system adopts a proton-transport catalysis strategy, in which chlorine atom coordination to the iron center is critical because it acts as a proton acceptor. When a molecule of water is involved in the Rh2(O2CCF3)4-catalyzed reaction, the 1,2-H shift is significantly promoted, so that the rate-determining step becomes the ring opening of 2-aryl-2H-azirine. In addition, we studied the catalytic activity of Fe(OAc)2 and CuCl.
authors: Department of Chemistry, Jinan University, Guangzhou, Guangdong 510632, P. R. China. tchjli@jnu.edu.cn.
authors: Caihong
authors: C
authors: Wu
authors: Juan
authors: J
authors: Li
authors: Bo
authors: B
authors: Yan
mesh_terms: D001389:Azirines / Q000737:chemistry*; D002384:Catalysis; D056831:Coordination Complexes / Q000737:chemistry*; D005296:Ferrous Compounds / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry*; D007536:Isomerism; D012238:Rhodium / Q000737:chemistry*
chemical_list: D001389:Azirines; D056831:Coordination Complexes; D005296:Ferrous Compounds; D007211:Indoles; D012238:Rhodium; C029451:ferrous chloride