||Synthesis of 3-Aryl-2-(trifluoromethyl)indoles via Copper-Catalyzed Hydroarylation and Subsequent Cadogan Cyclization
Yamamoto, Yoshihiko ,
Ohkubo, ErinaShibuya, Masatoshi
ADVANCED SYNTHESIS & CATALYSIS
1751 , 2017-05-17 , Wiley
The copper-catalyzed hydroarylation of (trifluoromethyl)alkynes with (o-nitrophenyl)boronic acids selectively afforded trisubstituted (trifluoromethyl)alkenes bearing an o-nitrophenyl group. The obtained hydroarylation products were converted into 3-aryl-2-(trifluoromethyl)indoles in high yields via molybdenum-catalyzed Cadogan cyclization. Similarly, the hydroarylation product prepared from (o-nitrophenyl)(trifluoromethyl)alkyne and (p-anisyl)boronic acid also underwent Cadogan cyclization, albeit with a longer reaction time, affording the desired indole product in a high yield.