Catalytic arylative cyclization of alkynals has been developed by the use of phosphine-free rhodium/dienecomplexes as catalysts. An asymmetric variant of this process has been successfully realized by employing a C2-symmetric chiral bicyclo[2.2.2]octadiene ligand. The rhodium/dienecatalyst system is also effective for arylative cyclization of other substrates such as alkynones and enynes, achieving multiple