InBr<sub>3</sub>: A Versatile Catalyst for the Different Types of Friedel−Crafts Reactions
作者:Ponnaboina Thirupathi、Sung Soo Kim
DOI:10.1021/jo9014613
日期:2009.10.16
Mild and efficient InBr3-catalyzed Friedel−Crafts alkylation of heteroaromatic or electron-rich aromatic compounds with α-amido sulfones at room temperature in CH2Cl2 has been developed. The products undergo further Friedel−Crafts alkylation with heteroaromatic or electron-rich aromatic compounds leading to unsymmetrical or bis-symmetrical triaryl methanes in good yield. α-Amido sulfones are employed
ABSTRACT A catalyst-freethree-componentreaction of indoles, carbonyls, and arenesulfinic acids performed at room temperature provides direct access to biologically important 3-(1-arylsulfonylalkyl)indoles. This process features mild conditions, low cost, broad substrate scope, and high yields, and mechanistically bis(indolyl)methanes were identified as the key intermediates. GRAPHICAL ABSTRACT
Tris(pentafluorophenyl)borane [B(C6F5)3]-catalyzed Friedel–Crafts reactions of activated arenes and heteroarenes with α-amidosulfones: the synthesis of unsymmetrical triarylmethanes
作者:Ponnaboina Thirupathi、Lok Nath Neupane、Keun-Hyeung Lee
DOI:10.1016/j.tet.2011.07.041
日期:2011.9
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.