Reductive Cyclization of o-Nitroarylated-α,β-unsaturated Aldehydes and Ketones with TiCl₃/HCl or Fe/HCl Leading to 1,2,3,9-Tetrahydro-4 H-carbazol-4-ones and Related Heterocycles

Qiu, YunDlugosch, MichaelLiu, XinKhan, FaiyazWard, JasLan, PingBanwell, Martin2019-07-250022-3263http://hdl.handle.net/1885/164713Compounds such as 3, the product of a palladium[0]-catalyzed Ullmann cross-coupling of o-iodonitrobenzene and 2-iodocyclohex-2-en-1-one, undergo complementary modes of reductive cyclization depending upon the conditions employed. Thus, on treatment with hydrogen in the presence of palladium on carbon, the tetrahydrocarbazole 4 is formed, while reaction of the same substrate (3) with TiCl3 in acetone affords the 1,2,3,9-tetrahydro-4H-carbazol-4-one 6.We thank the Australian Research Council, the Institute of Advanced Studies, Jinan University, the Pearl River Scholar Program of Guangdong Province, and the Famous Foreign Supervisor Program (Grant 2018-HWMS001) of the Ministry of Education, People’s Republic of China, for financial support.application/pdfen-AU© 2018 American Chemical SocietyReductive Cyclization of o-Nitroarylated-α,β-unsaturated Aldehydes and Ketones with TiCl₃/HCl or Fe/HCl Leading to 1,2,3,9-Tetrahydro-4 H-carbazol-4-ones and Related Heterocycles201810.1021/acs.joc.8b019402019-03-31