Easy, Green and Safe Carbonylation Reactions through Zeolite-Catalyzed Carbon Monoxide Production from Formic Acid

Palladium-Catalyzed Carbonylative Synthesis of Aryl Selenoesters Using Formic Acid as an Ex Situ CO Source

A new catalytic protocol for the synthesis of selenoesters from aryl iodides and diaryl diselenides has been developed, where formic acid was employed as an efficient, low-cost, and safe substitute for toxic and gaseous CO. This protocol presents a high functional group tolerance, providing access to a large family of selenoesters in high yields (up to 97%) while operating under mild reaction conditions, and avoids the use of selenol which is difficult to manipulate, easily oxidizes, and has a bad odor. Additionally, this method can be efficiently extended to the synthesis of thioesters with moderate-to-excellent yields, by employing for the first time diorganyl disulfides as precursors.

Rapid Organocatalytic Formation of Carbon Monoxide: Application towards Carbonylative Cross Couplings

Herein, the first organocatalytic method for the transformation of non‐derivatized formic acid into carbon monoxide (CO) is introduced. Formylpyrrolidine (FPyr) and trichlorotriazine (TCT), which is a cost‐efficient commodity chemical, enable this decarbonylation. Utilization of dimethylformamide (DMF) as solvent and catalyst even allows for a rapid CO generation at room temperature. Application towards four different carbonylative cross coupling protocols demonstrates the high synthetic utility and versatility of the new approach. Remarkably, this also comprehends a carbonylative Sonogashira reaction at room temperature employing intrinsically difficult electron‐deficient aryl iodides. Commercial ¹³C‐enriched formic acid facilitates the production of radiolabeled compounds as exemplified by the pharmaceutical Moclobemide. Finally, comparative experiments verified that the present method is highly superior to other protocols for the activation of carboxylic acids.

Transition-Metal-Free Acceptorless Decarbonylation of Formic Acid Enabled by a Liquid Chemical-Looping Strategy

The selective decarbonylation of formic acid was achieved under transition-metal-free conditions. Using a liquid chemical-looping strategy, the thermodynamically favored dehydrogenation of formic acid was shut down, yielding a pure stream of CO with no H₂ or CO₂ contamination. The transformation involves a two-step sequence where methanol is used as a recyclable looping agent to yield methylformate, which is subsequently decomposed to carbon monoxide using alkoxides as catalysts.

Supported Palladium Nanoparticles that Catalyze Aminocarbonylation of Aryl Halides with Amines using Oxalic Acid as a Sustainable CO Source

Polystyrene-supported palladium (Pd@PS) nanoparticles (NPs) have been used to catalyze the aminocarbonylation of aryl halides with amines using oxalic acid as a CO source for the first-time for the synthesis of amides. Furthermore, o-iodoacetophenones participated in amidation and cyclization reactions to give isoindolinones in a single step following a concerted approach. Oxalic acid has been used as a safe, environmentally benign and operationally simple ex situ sustainable CO source under double-layer-vial (DLV) system for different aminocarbonylation reactions. Catalyst stability under a CO environment is a challenging task, however, Pd@PS was found to be recyclable and applicable for a vast substrate scope avoiding regeneration steps. Easy handling of oxalic acid, additive and base-free CO generation, catalyst stability and effortless catalyst separation from the reaction mixture by filtration and introduce of DLV are the added advantages to make the overall process a sustainable approach.

Ureas as safe carbonyl sources for the synthesis of carbamates with deep eutectic solvents (DESs) as efficient and recyclable solvent/catalyst systems

A simple, efficient and eco-friendly one-pot synthesis of primary, N-mono- and N-disubstituted carbamates is developed from ureas.

Rhodium-catalyzed synthesis of esters from aryl iodides and alcohols: use of alcohols with/without the assistance of aldehydes as carbon monoxide and nucleophile sources

A CO-gas-free rhodium-catalyzed alkoxycarbonylation of aryl iodide with alcohols has been developed.

Mo(CO)6 as a Solid CO Source in the Synthesis of Aryl/Heteroaryl Weinreb Amides under Microwave-Enhanced Condition

The facile transformation of aryl/heteroaryl nonaflates into corresponding amides via Pd-catalyzed aminocarbonylation using Mo(CO)6 as a solid CO source under microwave-enhanced condition is reported. The method was found to be tolerant with respect to a diverse range of electronically biased aryl/heteroaryl nonaflates, and exceptional yields were obtained. The optimized protocol was further extended to a diverse range of amines.

A DFT Study of CO2 Hydrogenation on Faujasite-Supported Ir4 Clusters: on the Role of Water for Selectivity Control

Reaction mechanisms for the catalytic hydrogenation of CO₂ by faujasite‐supported Ir₄ clusters were studied by periodic DFT calculations. The reaction can proceed through two alternative paths. The thermodynamically favoured path results in the reduction of CO₂ to CO, whereas the other, kinetically preferred channel involves CO₂ hydrogenation to formic acid under water‐free conditions. Both paths are promoted by catalytic amounts of water confined inside the zeolite micropores with a stronger promotion effect for the reduction path. Co‐adsorbed water facilitates the cooperation between the zeolite Brønsted acid sites and Ir₄ cluster by opening low‐energy reaction channels for CO₂ conversion.

Low-cost instant CO generation at room temperature using formic acid, mesyl chloride and triethylamine

A simple and robust method for instant carbon monoxide generation at room temperature using easily accessible standard lab chemicals: formic acid, mesyl chloride and triethylamine.