Norbornylation of aromatics via complex techniques is described in the literature, but the literature also discloses that no direct, simple, and potentially low-cost methods are known. Larock et al. disclose a 43-74% yield of a mixture of exo-2-phenylnorbornane and the double insertion product (phenylated norbornene dimer) by reaction of norbornene with iodobenzene using a complex homogeneous catalyst system consisting of Pd(OAc).sub.2, n-Bu.sub.4 NCl, and formate salts such as KO.sub.2 CH. Larock, R. C., and Johnson, P. L., J. Chem Soc. Chem.Commun., 1638 (1989).
Brown, H. C. et al. describe preparation of exo-2-phenylnorbornane in 63.5% yield by norbornylation of benzene in excess benzene solvent, using large volumes of concentrated 2O sulfuric acid as the catalyst (weight ratio of concentrated H.sub.2 SO.sub.4 /norbornene of 2.2/1.0, mole ratio of H.sub.2 SO.sub.4 /norbornene of 2.7/1.0).