Unveiling the regioselectivity of rhodium(I)-catalyzed [2 + 2 + 2] cycloaddition reactions for open-cage C70 production.

The regioselective functionalization of fullerenes holds significant promise for applications in the fields of medicinal chemistry, materials science, and photovoltaics. In this study, we investigate the regioselectivity of the rhodium(I)-catalyzed [2 + 2 + 2] cycloaddition reactions between diynes and C70 as a novel procedure for generating C70 bis(fulleroid) derivatives. The aim is to shed light on the regioselectivity of the process through both experimental and computational approaches. In addition, the photooxidation of one of the C-C double bonds in the synthesized bis(fulleroids) affords open-cage C70 derivatives having a 12-membered ring opening.