Health & Environmental Research Online (HERO)


Print Feedback Export to File
7959139 
Journal Article 
Transition-Metal-Catalyzed Regioselective Alkylation of Indoles with Alcohols 
Putra, A; Takigawa, Kei; Tanaka, H; Ito, Y; Oe, Y; Ohta, T 
2013 
Yes 
European Journal of Organic Chemistry
ISSN: 1434-193X
EISSN: 1099-0690 
2013 
28 
6344-6354 
English 
WOS:000324932400020 
The regioselective alkylation of indoles with alcohols as alkylating reagents was developed by using Pd/C or RuCl2(PPh3) 3/DPEphos {DPEphos = bis[(2-diphenylphosphanyl)phenyl] ether}as catalysts. The reaction of indole with benzyl alcohol in the presence of Pd/C and K2CO3 at 80 °C for 24 h without any solvent under in air yielded 90 % of 3-benzylindole. The corresponding 3-benzylindole was obtained in 99 % yield when the reaction was catalyzed by RuCl 2(PPh3)3/DPEphos in the presence of K 3PO4 at 165 °C for 24 h under argon. Several types of alcohols were treated with indoles under these conditions to give the corresponding 3-alkylated indoles in high yields (up to 99 %). This reaction may involve the catalyst-mediated transformation of alcohols to aldehydes, nucleophilic addition of indole to the resulting aldehydes accompanied by dehydration, and then hydrogenation. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. 
Alkylation; Regioselectivity; Nitrogen heterocycles; Alcohols; Homogeneous catalysis; Heterogeneous catalysis