A new type of catalytically active palladium centers based on bimetallic molecular architecture

Palladium-catalyzed reactions of carbon-carbon and carbon-heteroatom bonds formation have been widely used over the past decades. Significant progress in the development of these approaches is associated with the creation of catalytic systems with high stereo-, regio-, and chemoselectivity. Palladium complexes have demonstrated their efficiency and extraordinary tolerance to a wide variety of functional groups in the construction of complex polyfunctional organic structures. However, metal species undergo complex transformations in the reaction system, which makes it difficult to determine the structure of active ones and, as a result, to design highly efficient catalysts.

Scientists of the Laboratory of Metal Complex and Nanoscale Catalysts of the ZIOC are among the world leaders in the field of studying the mechanisms of organic transformations catalyzed by transition metals. In one of their recent studies, they revised the widespread idea that dimeric metal complexes in many catalytic systems are not directly involved in catalytic processes. Thus, it was found that stable metal species with the M2X2 structure control catalytic cycles with the formation of a product without dissociation into monomers. Moreover, dimeric complexes may have improved selectivity and higher yields compared to monomeric analogs in the alkyne hydrothiolation process. Catalytically active species were detected in the reaction mixture using high resolution mass spectrometry and NMR spectroscopy. The importance of the research carried out goes far beyond the investigated hydrothiolation reaction. The results obtained will make it possible to identify new possible pathways for the processes and to predict intermediates for a wide range of substrates in various catalytic transformations.

Source:

Liliya T. Sahharova, Julia V. Burykina, Alexander Yu. Kostyukovich, Dmitry B. Eremin, Daniil A. Boiko, Artem N. Fakhrutdinov, Valentine P. Ananikov Expanding the Role of Dimeric Species: On-Cycle Involvement, Improved Stability, and Control of Stereo-Specificity. A Case Study of Atom-Economic Catalytic Hydrothiolation // ACS Catal. 2023, 13, 3591−3604. DOI: 10.1021/acscatal.2c06406.