furan ringopening proceed with heating. These data and results of control experiments showed that the reaction mechanism consists of three successive steps: recyclization itself, deacylation of the resulting N-acylindole, and furanringopening in N-unsubstituted 3-(2-furyl)indoles. The last step can be realized for N-unsubstituted indoles only, but the furanring is stable for N-acylindoles. This was
The effect of an N-substituent on the recyclization of (2-aminoaryl)bis(5-tert-butyl-2-furyl)methanes: synthesis of 3-furylindoles and triketoindoles
作者:Alexander V. Butin、Sergey K. Smirnov、Igor V. Trushkov
DOI:10.1016/j.tetlet.2007.11.015
日期:2008.1
The recyclization of (2-aminophenyi)bis(5-tert-butyl-2-furyl)methane derivatives has been studied. It was shown that the acid-catalyzed recyclization of N-tosylamides leads to the formation of 2-(3-oxoalkyl)-3-(2-furyl)indoles. In contrast, under the same reaction conditions, acetamides are transformed into indoles containing three keto groups. The acid-catalyzed removal of the acetyl group from these substrates facilitated protolytic furan ring opening. The same triketones can be directly obtained from (2-aminoaryl)bis(5-tert-butyl-2-furyl)methanes. (C) 2007 Elsevier Ltd. All rights reserved.