A cascade carbene insertion reaction on recoverable catalytic metal-free zeolites

Abstract

[EN] The generation and insertion reaction of carbenes is incompatible with strong oxidants or highly basic amino groups due to the rapid deactivation of the metal catalysts necessary to generate the carbenes. Here, we show that dealuminated zeolites are capable not only of generating and inserting carbenes from diazoacetates into O-H bonds, but also of allowing the in situ dehydrogenation reaction of the so-generated alcohol with (hydro)peroxides and the subsequent imination/isomerization (for non-aromatic imines) of the resulting ketoester with a primary amine, all in a one-pot catalytic mode. In this way, a variety of alpha-iminoesters can be generated from diazoacetates, water (also in catalytic amounts), and amines, with a recoverable and reusable solid catalyst. These results open the possibility of telescoping a carbene-mediated reaction with classical oxidation and condensation reactions in a cascade fashion, under the action of a simple and commercially available solid catalyst.