remains challenging, since the multiple unbiased C[double bond, length as m-dash]C bonds of terpenes lead to difficulty in controlling the regioselectivity. Herein, a cobalt(iii)-catalyzed C-H activation strategy has been developed to facilitate hydroxymethylarylation of terpenes with formaldehyde and arenes with high chemo- and regio-selectivities. These (chemo- and regio-) selectivities are governed by
atom-economical synthesis of (dl)-[α]-tocopherol (vitamin E) is proposed, the realization of which was made possible by the discovery of the regioselective Rh(I)-catalyzed arylation of β-springene with trimethylhydroquinone. Other phenolic compounds and 2-substituted-1,3-dienes were shown to undergo this transformation.