Polycyclic aromatic compounds and aromatic vinyl compounds are useful materials as various industrial starting materials. Examples of conventional processes for producing polycyclic aromatic compounds include a process in which aromatic halogen compounds are dehalogenated and coupled in the presence of a palladium catalyst and carbon monoxide, as described in JP-A-61-293932 (the term "JP-A" as used herein means an "unexamined published Japanese patent application"); and a process in which a phenylmagnesium halide is coupled with a phenyl halide in the presence of nickel chloride, as described in JP-A-63-295520. Examples of conventional processes for producing aromatic vinyl compounds include a process in which an olefin and an aromatic compound are subjected to an oxidative coupling reaction in the presence of a palladium catalyst under oxygen pressure, as described in Sekiyu Gakkai-shi (Journal of the Petroleum Society), Vol. 15, No.2, page 91 (1972).
However, the process, in which aromatic halogen compounds are dehalogenated and coupled in the presence of a palladium catalyst and carbon monoxide, has a problem in that polycyclic compounds having an unsymmetrical structure can not be obtained. The process, in which a phenylmagnesium halide is coupled with a phenyl halide in the presence of nickel chloride, has a disadvantage in that the phenylmagnesium halide is difficult to handle. Further, the process, in which an olefin and an aromatic compound are subjected to an oxidative coupling reaction in the presence of a palladium catalyst under oxygen pressure, has disadvantages in that since the reaction is carried out under oxygen pressure, there is a danger of explosion and selectivity is poor.