A rhodium-catalyzed efficient method for the synthesis of 2,3-dihydro-1H-indazoles is described. The reaction of arylhydrazines with olefins results in the corresponding 2,3-dihydro 1H-indazoles with exclusive regioselectivity via CâH bond activation. The utility of the methodology is illustrated by a rapid synthesis of 1H-indazoles under mild reaction conditions in half an hour.
Rh(III)-Catalyzed Oxidative Coupling of 1,2-Disubstituted Arylhydrazines and Olefins: A New Strategy for 2,3-Dihydro-1<i>H</i>-Indazoles
作者:Sangil Han、Youngmi Shin、Satyasheel Sharma、Neeraj Kumar Mishra、Jihye Park、Mirim Kim、Minyoung Kim、Jinbong Jang、In Su Kim
DOI:10.1021/ol500865j
日期:2014.5.2
A rhodium(III)-catalyzed oxidative olefination of 1,2-disubstituted arylhydrazines with alkenes via sp(2) C-H bond activation followed by an intramolecular aza-Michael reaction is described. This strategy allows the direct and efficient construction of highly substituted 2,3-dihydro-1H-indazole scaffolds.
Formation of Enehydrazine Intermediates through Coupling of Phenylhydrazines with Vinyl Halides: Entry into the Fischer Indole Synthesis
作者:Fuxu Zhan、Guangxin Liang
DOI:10.1002/anie.201207173
日期:2013.1.21
Cut to the chase: Direct formation of an enehydrazine, an intermediate in the classic Fischerindolesynthesis, solves the regioselectivity problem associated with indolization. This approach not only achieves selective synthesis of indoles through proper selection of the vinyl halide, but also leads to quick construction of desoxyeseroline and esermethole, as well as the key structural motif in the