Indirect reduction of CO₂and recycling of polymers by manganese-catalyzed transfer hydrogenation of amides, carbamates, urea derivatives, and polyurethanes

Abstract

The reduction of polar bonds, in particular carbonyl groups, is of fundamental importance in organic chemistry and biology. Herein, we report a manganese pincer complex as a versatile catalyst for...

Evaluation of Manganese Catalysts for the Hydrogenative Deconstruction of Commercial and End‐of‐Life Polyurethane Samples

“…During the preparation of this manuscript, Schaub and coworkers reported an alternative Mn catalyst for the catalytic hydrogenative deconstruction of commercial and end-of-life polyurethane materials, [62] whereas Liu and Werner reported a transfer hydrogenation process for the reductive cleavage of simple linear polyurethanes with Mn-4 d. [63] Scheme 2. Gram-scale Mn-Ph MACHO-catalyzed hydrogenation of flexible foam (PU-2).…”

Hydrogenative Depolymerization of Polyurethanes Catalyzed by a Manganese Pincer Complex

“…The recycling of real-life polyurethanes has not been addressed in the report. [11] However, it is highly desirable to develop an efficient catalytic system based on an earth-abundant metal, as a cheaper and greener alternative to precious transition metal catalysts.…”

Manganese-catalyzed hydrogenation, dehydrogenation, and hydroelementation reactions

“…The only report on the TH of amides, carbamates, and urea derivatives was disclosed by Werner's group (Scheme 27). 173 The Ph MACHO–Mn( i ) pincer complex Mn39 was employed in the presence of 6 mol% KO t Bu as base and i PrOH as a sacrificial H 2 donor at 100 °C. Both aliphatic and aromatic primary or secondary amides underwent smooth hydrogenative cleavage of the C–N bond to amines and alcohols.…”