Pd-catalyzed Carbonylative Coupling Research Articles

Synthesis of Cross-Linked Pseudopeptides Using Pd-Catalyzed Carbonylative Coupling

Synthesis of Cross-Linked Pseudopeptides Using Pd-Catalyzed Carbonylative Coupling

Computational Exploration of Mechanistic Avenues in C-H Activation Assisted Pd-Catalyzed Carbonylative Coupling.

The detailed mechanism of the intermolecular Pd-catalyzed carbonylative coupling reaction between aryl bromides and polyfluoroarenes relying on C(sp2)-H activation was investigated using state-of-the-art computational methods (SMD-B3LYP-D3(BJ)/BS2//B3LYP-D3/BS1). The mechanism unveils the necessary and important roles of a slight excess of carbon monoxide: acting as a ligand in the active catalyst state, participating as a reactant in the carbonylation process, and accelerating the final reductive elimination event. Importantly, the desired carbonylative coupling route follows the rate-limiting C-H activation process via the concerted metalation-deprotonation pathway, which is slightly more feasible than the decarboxylative route leading to byproduct formation by 1.2 kcal/mol. The analyses of the free energies indicate that the choice of base has a significant effect on the reaction mechanism and its energetics. The Cs2CO3 base guides the reaction toward the coupling route, whereas carbonate bases such as K2CO3 and Na2CO3 switch toward an undesired decarboxylative path. However, K3PO4 significantly reduces the C-H activation barrier over the decarboxylation reaction barrier and can act as a potential alternative base. The positional influence of a methoxy substituent in bromoanisole and different substituent effects in polyfluoroarenes were also considered. Our results show that different substituents impose significant impact on the desired carbonylative product formation energetics. Considering the influence of several ligands leads to the conclusion that other phosphine and N-heterocyclic carbene, such as P nBuAd2 and IMes, can be used as an efficient alternative than the experimentally reported P tBu3 ligand exhibiting a clear preference for C-H activation (ΔΔ⧧ GLS) by 7.1 and 10.9 kcal/mol, respectively. We have also utilized the energetic span model to interpret the experimental results. Moreover, to elucidate the origin of activation barriers, energy decomposition analysis calculations were accomplished for the critical transition states populating the energy profiles.

Synthesis of acyl carbamates via four component Pd-catalyzed carbonylative coupling of aryl halides, potassium cyanate, and alcohols.

A simple and mild method is demonstrated for assembling acyl carbamates through a base-free four-component Pd-catalyzed carbonylation of aryl halides in the presence of potassium cyanate and alcohols in a two-chamber system. This approach produces a wide range of aryl acyl carbamates in good to excellent yields from the corresponding aryl bromides or iodides with near-stoichiometric carbon monoxide. In addition, the method can be extended to the synthesis of primary amides thereby expanding the usefulness of cyanate as an ammonia equivalent.

C–H activation dependent Pd-catalyzed carbonylative coupling of (hetero)aryl bromides and polyfluoroarenes

The carbonylative coupling of aryl and heteroaryl bromides with polyfluoroarenes via palladium-catalyzed C-H activation is presented. This transformation proceeds efficiently at moderate reaction temperatures and does not require strong base or reactive intermediates. A near stoichiometric amount of CO is sufficient and the methodology can thus be easily expanded to include the preparation of [(13)C]-acyl labeled benzopolyfluorophenones.

ChemInform Abstract: Base‐Controlled Selectivity in the Synthesis of Linear and Angular Fused Quinazolinones by a Palladium‐Catalyzed Carbonylation/Nucleophilic Aromatic Substitution Sequence.

AbstractThe Pd‐catalyzed carbonylative coupling of ortho‐fluoro substituted bromobenzenes with 2‐aminopyridines is reported.

Pd-Catalyzed Carbonylative Coupling of Aryl Halides and Potassium Malonates

Pd-Catalyzed Carbonylative Coupling of Aryl Halides and Potassium Malonates

An Efficient Synthesis of 2,4-Substituted [1,8]Naphthyridines from 3-(2-Amino-5-methylpyridin-3-yl)-1-arylprop-2-yn-1-ones

3-(2-Amino-5-methylpyridin-3-yl)-1-arylprop-2-yn-1-ones 2, readily available through Pd-catalyzed carbonylative coupling of 5-methyl-3-[2-(trimethylsilyl)ethynyl]pyridine-2-ylamine (1) with aryl iodides in the presence of carbon monoxide, undergo a domino conjugate addition/annulation reaction to give 4-heterosubstituted 2-aryl[1,8]naphthyridines 3 in high yields.

Palladium-Catalyzed Carbonylative Coupling of Arylfluorosilanes with Aryl Iodides. A Convenient Synthesis of Diaryl Ketones

Abstract In the presence of 1 atm of carbon monoxide, arylfluorosilanes activated by potassium fluoride were found to participate in the Pd-catalyzed carbonylative coupling reaction of aryl iodides to give unsymmetrical diaryl ketones in good yields.