InBr3: A Versatile Catalyst for the Different Types of Friedel-Crafts Reactions

Mild and efficient InBr3-catalyzed Friedel-Crafts alkylation of heteroaromatic or electron-rich aromatic compounds with alpha-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. alpha-Amido sulfones are employed for the synthesis of the unsymmetrical and bis-symmetrical triaryl methanes. The use of mild reaction condition, low catalytic loading, and high yield are the advantages of the present procedures.