A New Class of Chelating N-Heterocyclic Carbene Ligands and Their Complexes with Palladium

A new series of chelating N-heterocyclic carbene (NHC) ligands and their complexes with palladium are described. The ligands feature a chelating phenolic unit, thereby expanding the class of available NHC ligands for organometallic catalysis

Organometallic catalysis in biological media and living settings

Organometallic catalysis has allowed the development of an impressive number of chemical transformations that could not be achieved using classical methodologies. Most of these reactions have been accomplished in organic solvents, and in many cases in the absence of water, and under air-free conditions. The increasing pressure to develop more sustainable transformations has stimulated the discovery of metal-catalyzed reactions that can take place in water. A particularly attractive extension of this chemistry consists of the use of biological relevant aqueous solvents, as this might set the basis to translate catalytic metal complexes to biological settings. While this research field is in its infancy, along the last ten years there have been an increasing number of reports demonstrating the viability of achieving metal-promoted transformations in biologically relevant contexts. In this review, that does not intend to be comprehensive, we summarize the most significant advances in the area, and highlight some of the more important difficulties that must be faced when trying to design biocompatible organometallic catalysts, such us stability, cell uptake, bioorthogonality and toxicity. We will manly focus on transition metal systems which have been shown to keep their activity in complex aqueous buffers and inside living cellsWe are thankful for the financial support from the Xunta de Galicia (Centro singular de investigación de Galicia accreditation 2016–2019) and the European Union (European Regional Development Fund – ERDF). We also thank support given by the Spanish grantsSAF2013-41943-R and SAF2016-76689-R, the Xunta de Galicia (GRC2013-041 and 2015-CP082), the ERDF, and the European Research Council (Advanced Grant No. 340055). MMC thanks the Ministerio de Economía y Competitividad for the Postdoctoral fellowship (IJCI-2014-19326)S

Organometallic catalysis for applications in radical chemistry and asymmetric synthesis

Two organometallic catalysis studies are presented. The first one deals with the development of a new catalytic agent based on the mixture of a hydride and an iron salt to trigger efficient radical cyclization processes. In a second line of research, we have shown that the use of chiral anions can outperform chiral ligands in a carbocyclization reaction and a 2 + 2 + 2 cycloaddition

Coordinating Anions: (Phosphino)tetraphenylborate Ligands as New Reagents for Synthesis

Anionic, electron-releasing phosphines that incorporate a borate counteranion within the ligand framework are promising reagents for organometallic catalysis. This report describes the synthesis of a new class of monodentate tertiary phosphines built upon the commonly employed tetraphenylborate anion. These new phosphines are highly stable and strongly electron-releasing and readily coordinate transition metals. Moreover, they are promising reagents for catalysis, as demonstrated by their ability to promote the Suzuki cross-coupling of aryl chloride substrates

Copper-Free Oxime–Palladacycle-Catalyzed Sonogashira Alkynylation of Deactivated Aryl Bromides and Chlorides in Water under Microwave Irradiation

Palladium-catalyzed Heck alkynylation cross-coupling reactions between terminal alkynes and deactivated aryl chlorides and aryl bromides can be performed in the absence of copper cocatalyst with water as solvent at 130 °C under microwave irradiation. An oxime-derived chloro-bridged palladacycle is an efficient precatalyst for this transformation with 2-dicyclohexylphosphanyl-2′,4′,6′-triisopropylbiphenyl (XPhos) as ancillary ligand, pyrrolidine as base, and SBDS as surfactant. All of the reactions can be performed under air and with reagent-grade chemicals under low loading conditions (0.1–1 mol-% Pd).Financial support from the Ministerio de Economía y Competitividad (MINECO) (project CTQ2010-20387), Consolider INGENIO (project 2010 CSD2007-00006), Fondos Europeos para el Desarrollo Regional (FEDER), the Generalitat Valenciana (project PROMETEO/2009/038), and the University of Alicante is acknowledged

Faculty Research Profile: Stefan M. Kilyanek

This poster was compiled to commemorate the promotion of Dr. Stefan M. Kilyanek to associate professor with tenure in the Department of the Chemistry and Biochemistry at the University of Arkansas in July 2020. It provides a summary of his research achievements and their scholarly impact

Развитие агропромышленного комплекса России в новых исторических условиях второго десятилетия XXI в.

Carbon dioxide in its liquid or supercritical state (scCO(2)) has a prodigious potential as an environmentally benign reaction medium for sustainable chemical synthesis. Since the mid-1990s, rapidly increasing research efforts have shown that scCO(2) can replace conventional and potentially hazardous solvents in a wide range of processes. There is also increasing evidence that the application of scCO(2) can broaden the scope of catalytic synthetic methodologies. On the basis of the experience in our laboratories, this report analyzes the impact of scCO(2) on green organometallic catalysis