Cs ₂ CO ₃ ‐Promoted aza‐Michael Addition of ( <i>E</i> )‐ <i>β</i> ‐Iodovinyl Sulfones with 5‐Amino‐1 <i>H</i> ‐pyrazole‐4‐carbaldehydes and Anthranilic Acids/Amides: Synthesis of 5‐Sulfonylpyrazolo[3,4‐ <i>b</i> ]pyridines and

Abstract Metal‐free tandem synthesis of 5‐sulfonyl‐pyrazolo[3,4‐ b ]pyridines and 3‐sulfonyl‐4‐quinolones is accomplished by reacting 5‐amino‐1 H ‐pyrazole‐4‐carbaldehydes/carboxylic acids and anthranilic acids/amides independently with ( E )‐ β ‐iodovinyl sulfones in presence of Cs 2 CO 3 involving [4+2] cycloaddition. The reaction proceeds via an aza‐Michael addition followed by intramolecular cyclization forming a new C─N and C─C bonds. This is the first protocol to synthesize title products using ( E )‐ β ‐iodovinyl sulfones as a key synthon.