861631-61-0Relevant articles and documents
A highly active catalyst for the reductive cyclization of ortho-nitrostyrenes under mild conditions
Davies, Ian W.,Smitrovich, Jacqueline H.,Sidler, Rick,Qu, Chuanxing,Gresham, Venita,Bazaral, Charles
, p. 6425 - 6437 (2007/10/03)
A mild and efficient method for the palladium-catalyzed reductive cyclization of ortho-nitrostyrenes to afford indoles is reported. Treatment of ortho-nitrostyrenes with 0.1 mol% palladium (II) trifluoroacetate [Pd(TFA) 2] and 0.7 mol% 3,4,7,8-tetramethyl-1,10-phenanthroline (tm-phen) in DMF at 15 psig CO and 80°C afforded indoles in good to excellent yields. When the reaction was conducted in toluene, the corresponding N-hydroxyindole was isolated. A mechanism that accounts for the formation of N-hydroxyindole is proposed.