Five-Component [2 + 2 + 1 + 1] Tandem Benzannulation Leading to Multifunctionalized Aromatic Amines.

An unprecedented five-component [2 + 2 + 1 + 1] benzannulation strategy for regioselective assembly of densely functionalized aromatic amines from two ynals, two malononitriles, and sodium sulfinates is established. The benzannulation protocol enables the efficient installation of five substituents on a benzene ring via the formation of multiple chemical bonds in a single operation, providing various multifunctionalized aromatic primary amines in moderate to good yields. Additionally, three-component [3 + 2 + 1] cycloaddition of malononitriles, ynals, and NH4SCN was also achieved to produce 2-amnopyridine derivatives with NH4SCN serving as an ammonia surrogate.