Tris(pentafluorophenyl)borane [B(C6F5)3]-catalyzed Friedel–Crafts reactions of activated arenes and heteroarenes with α-amidosulfones: the synthesis of unsymmetrical triarylmethanes
摘要:
Tris(pentafluorophenyl)borane [B(C6F5)(3)] has found to be an efficient catalyst for Friedel-Crafts reactions between activated arenes or heteroarenes and alpha-amidosulfones. The products undergo further Friedel-Crafts reactions with activated heteroarenes leading to the synthesis of unsymmetrical triarylmethanes. The present synthetic method displayed significant advantages such as low catalyst loading, mild reaction conditions, highly regioselective, high yield, and broad applicability to various substrates. (C) 2011 Elsevier Ltd. All rights reserved.
Regioselective Arylations of α-Amido Sulfones with Electron-Rich Arenes through Friedel-Crafts Alkylations Catalyzed by Ferric Chloride Hexahydrate: Synthesis of Unsymmetrical and Bis-Symmetrical Triarylmethanes
作者:Ponnaboina Thirupathi、Sung Soo Kim
DOI:10.1002/ejoc.200901186
日期:2010.3
Ferricchloridehexahydrate is a highly efficient catalyst for the regioselectivearylation of α-amidosulfones. The products undergo further Friedel-Craftsalkylations with heteroaromatic or electron-richarenes to afford unsymmetrical or bis-symmetricaltriarylmethanes.
alpha-Amido sulfones undergo aza-Morita-Baylis-Hillman reaction efficiently with alkyl acrylates under neat conditions in the presence of DABCO at room temperature. These sulfones generate aryl imines in the presence of DABCO and form the corresponding adducts in high yields (85-94%) within 9-12 h. (C) 2008 Elsevier Ltd. All rights reserved.