Synthesis of 6-bromo-2-arylindoles using 2-iodobenzoic acid as precursor
摘要:
The synthesis of 6-bromo-2-arylindoles starting from readily available 2-iodobenzoic acid is presented. Regioselective bromination of the latter was followed by Curtius rearrangement and trapping of the isocyanate with benzyl alcohol led to the benzyl carbamate of 2-iodo-5-bromoaniline. Chemoselective Sonogashira coupling of this compound with arylacetylenes followed by TBAF induced 5-endo-dig cyclization gave the desired bromo indoles. The method allows selective introduction of a bromine atom at the indole C-6 position. (C) 2011 Elsevier Ltd. All rights reserved.
Synthesis of 6-bromo-2-arylindoles using 2-iodobenzoic acid as precursor
作者:Ismael Valois-Escamilla、Alejandro Alvarez-Hernandez、Luis Felipe Rangel-Ramos、Oscar Rodolfo Suárez-Castillo、Francisco Ayala-Mata、Gerardo Zepeda-Vallejo
DOI:10.1016/j.tetlet.2011.05.040
日期:2011.7
The synthesis of 6-bromo-2-arylindoles starting from readily available 2-iodobenzoic acid is presented. Regioselective bromination of the latter was followed by Curtius rearrangement and trapping of the isocyanate with benzyl alcohol led to the benzyl carbamate of 2-iodo-5-bromoaniline. Chemoselective Sonogashira coupling of this compound with arylacetylenes followed by TBAF induced 5-endo-dig cyclization gave the desired bromo indoles. The method allows selective introduction of a bromine atom at the indole C-6 position. (C) 2011 Elsevier Ltd. All rights reserved.