Double-Carrousel Mechanism for Mn-Catalyzed Dehydrogenative Amide Synthesis from Alcohols and Amines
Jesús Antonio Luque‐Urrutia, Tània Pèlachs, Miquel Solà, Albert Poater
Abstract
We study with density functional theory calculations the mechanism of the original example of a base-metal-catalyzed synthesis of amides from alcohols and amines. A preliminary proposal of the mechanism of this reaction was experimentally reported by Milstein and co-workers. Instead of the proposed reaction mechanism with a hemilabile pincer amine arm, our DFT calculations describe a facile protocol, where the catalyst only produces aldehydes from alcohols. Once formaldehyde is formed from methanol, it reacts with the amine to form a second alcohol. This new alcohol undergoes the same procedure as methanol and creates the desired amide through a double-carrousel mechanism. The rate-determining step in the catalytic aldehyde synthesis corresponds to the H2 formation. However, in the nonmetal-catalyzed part of the mechanism, the interaction of formaldehyde with the amine is also quite kinetically demanding