1627687-20-0Relevant articles and documents
Studies on [PtCl2]- or [AuCl]-catalyzed cyclization of 1-(indol-2-yl)-2,3-allenols: The effects of water/steric hindrance and 1,2-migration selectivity
Qiu, Youai,Fu, Chunling,Zhang, Xue,Ma, Shengming
supporting information, p. 10314 - 10322 (2014/08/18)
The [PtCl2]- or [AuCl]-catalyzed reaction of 1-(indol-2-yl)-2,3-allenols occurred smoothly at room temperature to afford a series of poly-substituted carbazoles efficiently. Compared with the [PtCl 2]-catalyzed process, the [AuCl]-catalyzed reaction represents a significant advance in terms of the scope and the selectivity. Selective 1,2-alkyl or aryl migration of the gold carbene intermediate was observed: compared with the methyl group, the isopropyl, cyclopropyl, cyclobutyl, and cyclohexyl groups migrate exclusively; the cyclopropyl group shifts selectively over the ethyl group; the 1,2-migration of a non-methyl linear alkyl is faster than methyl group; the phenyl group migrates exclusively over methyl or ethyl group. DFT calculations show that water makes the elimination of H2O facile requiring a much lower energy and validates the migratory preferences of different alkyl or phenyl groups observed.
