Carboxylation of indoles and pyrroles with CO 2 in the presence of dialkylaluminum halides

K Nemoto, S Onozawa, N Egusa, N Morohashi…

Index: Nemoto, Koji; Onozawa, Satoru; Egusa, Naoki; Morohashi, Naoya; Hattori, Tetsutaro Tetrahedron Letters, 2009 , vol. 50, # 31 p. 4512 - 4514

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Citation Number: 22

Abstract

The Lewis acid-mediated carboxylation of arenes with CO2 has been successfully applied to 1-substituted indoles and pyrroles by using dialkylaluminum chlorides instead of aluminum trihalides. Thus, the carboxylation of 1-methylindoles, 1-benzyl-, and 1-phenylpyrroles proceeds regioselectively with the aid of an equimolar amount of Me2AlCl under CO2 pressure (3.0 MPa) at room temperature to afford the corresponding indole-3-carboxylic ...