FeCl3•6H2O catalyzed three components aza-Friedel-Crafts reaction For the synthesis of N-Boc protected α-branched amines
Authors
Sureeporn Ruengsangtongkul
Department of Chemistry and Center for Innovation in Chemistry, Faculty of Science, Burapha University, Bangsaen,
Chonburi, 20131 Thailand
Jaray Jaratjaroonphong
Department of Chemistry and Center for Innovation in Chemistry, Faculty of Science, Burapha University, Bangsaen,
Chonburi, 20131 Thailand
Abstract
FeCl3•6H2O is shown to be an efficient catalyst for the three component aza-Friedel-Crafts reaction of arenes or heteroarenes, tert-butyl carbamate, and aromatic aldehydes under mild conditions. In the presence of 5 mol % of FeCl3•6H2O in toluene at room temperature, the reaction of 1,3,5-trimethoxybenzene, 2-methyl furan, and 2-ethylfuran gave the corresponding N-Boc protected α-branched amines, selectively, in moderate to excellent yields. However, the reaction of the less reactive 2-methylthiophene afforded the α-branched amine adducts in low yield. On the other hand, the reaction of indole gave the triarylmethane as major product. The use of mild reaction condition, commercially available as well as inexpensive catalyst, low catalyst loading, and single step synthesis are the advantage of the presence procedure.
