Transition-metal-catalyzed C-H bond activation as a sustainable strategy for the synthesis of fluorinated molecules: an overview.

The last decade has witnessed the emergence of innovative synthetic tools for the synthesis of fluorinated molecules. Among these approaches, the transition-metal-catalyzed functionalization of various scaffolds with a panel of fluorinated groups (XR, X = S, Se, O) offered straightforward access to high value-added compounds. This review will highlight the main advances made in the field with the transition-metal-catalyzed functionalization of C(sp) and C(sp) centers with SCF, SeCF, or OCHCF groups among others, by C-H bond activation.

Synthesis and Catalytic Properties of a Very Latent Selenium-Chelated Ruthenium Benzylidene Olefin Metathesis Catalyst.

Herein, we describe a study of the synthesis, characterization, and catalytic properties of a -dichlorido seleno-chelated Hoveyda-Grubbs type complex (). Such a complex has been obtained through a straightforward and high-yielding synthetic protocol in three steps from the commercially available 2-bromobenzaldehyde in good overall yield (54%). The catalytic profile, especially the latency of this complex, has been probed through selected olefin metathesis reactions such as ring-closing metathesis (RCM), self-cross-metathesis (self-CM) and ring-opening metathesis polymerization (ROMP).

Uranyl(VI) Triflate as Catalyst for the Meerwein-Ponndorf-Verley Reaction.

Catalytic transformation of oxygenated compounds is challenging in f-element chemistry due to the high oxophilicity of the f-block metals. We report here the first Meerwein-Ponndorf-Verley (MPV) reduction of carbonyl substrates with uranium-based catalysts, in particular from a series of uranyl(VI) compounds where [UO(OTf)] () displays the greatest efficiency (OTf = trifluoromethanesulfonate). [UO(OTf)] reduces a series of aromatic and aliphatic aldehydes and ketones into their corresponding alcohols with moderate to excellent yields, using PrOH as a solvent and a reductant.

Ruthenium Olefin Metathesis Catalysts Featuring N-Heterocyclic Carbene Ligands Tagged with Isonicotinic and 4-(Dimethylamino)benzoic Acid Rests: Evaluation of a Modular Synthetic Strategy.

A modular and flexible strategy towards the synthesis of N-heterocyclic carbene (NHC) ligands bearing Brønsted base tags has been proposed and then adopted in the preparation of two tagged NHC ligands bearing rests of isonicotinic and 4-(dimethylamino)benzoic acids. Such tagged NHC ligands represent an attractive starting point for the synthesis of olefin metathesis ruthenium catalysts tagged in non-dissociating ligands. The influence of the Brønsted basic tags on the activity of such obtained olefin metathesis catalysts has been studied.

Ruthenium Complexes Featuring Unsymmetrical N-Heterocyclic Carbene Ligands-Useful Olefin Metathesis Catalysts for Special Tasks.

This review describes a distinct class of ruthenium olefin metathesis catalysts featuring unsymmetrical N-heterocyclic carbene (uNHC) ligands, from its historical beginning to the present state of the art. Thanks to advantageous traits, such as pronounced thermodynamic stability, chemical latency, outstanding selectivity, and compatibility with green solvents, these catalysts led to good results in a number of specialized metathesis transformations. Therefore, while being a niche, the uNHC complexes can potentially be implemented in a number of industrial processes, such as valorization of Fischer-Tropsch olefin fractions, ethenolysis of renewable products, and modern pharmaceutical production.

Preparation of Functionalized α,β-Unsaturated Sulfonamides via Olefin Cross-Metathesis.

The synthesis of functionalized α,β-unsaturated sulfonamides by means of cross-metathesis of vinyl sulfonamides and olefins has been developed. The reaction proceeds smoothly in the presence of Hoveyda-Grubbs catalyst and its nitro analogue, providing a wide range of substituted products. The usefulness of this methodology has been proven in the preparation of new derivatives of biologically active ingredients, moxifloxacin and naratriptan.