Click
chemistry, which refers to chemical reactions that are fast
and selective with high product yields, has become a powerful approach
in organic synthesis and chemical biology. Due to the cytotoxicity
of the transition metals employed in click chemistry reactions, a
search for novel metal-free alternatives continues. Herein, we demonstrate
that an optical cavity can be utilized as a metal-free alternative
in the click chemistry cycloaddition reaction between cyanoacetylene
and formylazide using the quantum electrodynamics coupled cluster
method. We show that by changing the molecular orientation with respect
to the polarization of the cavity mode(s), the reaction can be selectively
catalyzed to form a major 1,4-disubstituted or 1,5-disubstituted product.
This work highlights that a cavity has the same effect on the investigated
cycloaddition as the transition metal catalysts traditionally employed
in click chemistry reactions. We expect our findings to further stimulate
research on cavity-assisted click chemistry reactions.