Efficient reagents for the synthesis of 5-, 7-, and 5, 7-substituted indoles starting from aromatic amines: Scope and limitations

…, C Pedregal, C Lamas, J Barluenga…

Index: Ezquerra, Jesus; Pedregal, Concepcion; Lamas, Carlos; Barluenga, Jose; Perez, Marta; Garcia-Martin, Miguel Angel; Gonzalez, Jose M. Journal of Organic Chemistry, 1996 , vol. 61, # 17 p. 5804 - 5812

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Citation Number: 192

Abstract

Upon reaction with IPy2BF4, 4-substituted anilines give regioselectively the corresponding o- iodoanilines in nearly quantitative yield, in a process that can be carried out on a multigram scale. Palladium-catalyzed coupling of the resulting 2-iodoanilines with (trimethylsilyl) acetylene (TMSA), followed by efficient CuI-mediated nitrogen cyclization onto alkynes with concurrent elimination of the TMS substituent, allows a straightforward elaboration of 5- ...