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
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.
Copper‐Catalyzed Trifunctionalization of Alkynes: Rapid Formation of Oxindoles Bearing Geminal Diboronates
作者:Tao He、Bin Li、Li‐Chuan Liu、Jing Wang、Wen‐Peng Ma、Guang‐Yu Li、Qing‐Wei Zhang、Wei He
DOI:10.1002/chem.201804480
日期:——
A copper‐catalyzed trifunctionalization of alkynes that provides rapid access to oxindoles bearing a geminal diboronate side chain, highlighted by the simultaneous formation of one C−C bond and two C−B bonds, is reported. This new reaction features simple reaction conditions (ligand‐free catalysis), a general substrate scope, and excellent chemoselectivity. Mechanistic study revealed a reaction sequence