Exploring a potential catalyst system for catalyst‐controlled selectivity in C−Sbondformation is a fascinating challenge. Herein, we described two novel and highlyefficient methods for the selectivesynthesis of C2‐ and C3‐sulfonylindoles showing good biological activities by employing iodide and copper catalysts, respectively. Mechanistic studies point to the crucial role of the electronic properties
InBr3-catalyzed sulfonation of indoles: a facile synthesis of 3-sulfonyl indoles
作者:J.S. Yadav、B.V.S. Reddy、A.D. Krishna、T. Swamy
DOI:10.1016/s0040-4039(03)01507-7
日期:2003.8
Indoles react smoothly with sulfonyl chlorides in the presence of a catalytic amount of indium tribromide at ambient temperature to afford the corresponding 3-arylsulfonyl indole derivatives in high yields with high regioselectivity.
In this paper, a simple and efficient protocol for the chemoselective sulfonation of indoles using aryl sulfonyl chlorides in the presence of CuI is reported. The reaction proceeds under mild conditions and is applicable to indoles bearing a selection of functional groups without NH protection.[GRAPHICS].