Kálmán J. Szabó

Electrophilic Trifluoromethylation by Copper-Catalyzed Addition of CF3-Transfer Reagents to Alkenes and Alkynes

Regio- and stereoselective Cu-catalyzed addition of the above hypervalent iodine reagent to alkynes and alkenes was achieved. In the presence of CuI, the reaction is suitable to perform trifluoromethyl-benzoyloxylation and trifluoromethyl-halogenation of alkenes and alkynes. Electron-donating substituents accelerate the process, and alkenes react faster than alkynes emphasizing the electrophilic character of the addition reaction.

Pincer and pincer-type complexes : applications in organic synthesis and catalysis

Preface CATALYSIS BY PINCER COMPLEXES: SYNTHESIS OF ESTERS, AMIDES, AND PEPTIDES Introduction and Background Bond Activatio by Metal-Ligand Cooperation Synthesis of Esters Synthesis of Amides Synthesis of Peptides from Beta-Amino Alcohols Concluding Remarks THE ROLE OF REDOX PROCESSES IN REACTIONS CATALYZED BY NICKEL AND PALLADIUM COMPLEXES WITH ANIONIC PINCER LIGANDS Introduction Pincer Complexes of Ni, Pd, and Pt in Oxidation States Different from II Catalytic Reactions Involving Redox Processes in the Pincer-Metal Framework Concluding Remarks APPENDED FUNCTIONALITY IN PINCER LIGANDS Introduction Appended Functionality Coplanar with the Pincer Chelate Appended Functionality Not Coplanar to the Pincer Chelate Future Outlook and Summary C-C, C-O, AND C-B BOND FORMATION BY PINCER COMPLEXES INCLUDING ASYMMETRIC CATALYSIS Introduction - Pros and Cons of Using Pincer Complexes in Catalysis Reaction of Imines and Isocyanoacetates C-H Functionalization of Organonitriles Reactions Involving Hypervalent Iodines Summary and Outlook NICKEL-CATALYZED CROSS-COUPLING REACTIONS Introduction Carbon-Carbon Bond-Forming Reactions Carbon-Heteroatom Bond-Forming Reactions Summary and Outlook PSiP TRANSITION-METAL PINCER COMPLEXES: SYNTHESIS, BOND ACTIVATION, AND CATALYSIS Introduction PSiP Ligand Syntheses Group 8 Metal PSiP Chemistry Group 9 Metal PSiP Chemistry Group 10 Metal PSiP Chemistry Group 11 Metal PSiP Chemistry Alternative Silyl Pincers Summary ELECTRONIC STRUCTURES OF REDUCED MANGANESE, IRON, AND COBALT COMPLEXES BEARING REDOX-ACTIVE BIS(IMINO)PYRIDINE PINCER LIGANDS Introduction Reduced Manganese, Iron, and Cobalt Complexes with Redox-Active Bis(imino)pyridines Conclusions and Outlook PINCER COMPLEXES WITH SATURATED FRAMEWORKS: SYNTHESIS AND APPLICATIONS Introduction Synthesis of the Ligands Synthesis and Coordination Behavior of Carbometallated PC(sp3)P Complexes Reactivity and Catalytic Applications of PC(sp3) Complexes HEAVIER GROUP 14 ELEMENTS-BASED PINCER COMPLEXES IN CATALYTIC SYNTHETIC TRANSFORMATIONS OF UNSATURATED HYDROCARBONS Introduction Synthesis of Palladium Complexes Bearing PXP-Pincer Ligands (X=Si, Ge, Sn) Hydrocarboxylation Reductive Aldol Type Reaction Dehydrogenative Borylation Synthesis and Reaction of n2-(Si-H)Pd(0) Complex as an Equivalent to PSiP-Palladium Hydride Complexes Conclusions EXPERIMENTAL AND THEORETICAL ASPECTS OF PALLADIUM PINCER-CATALYZED C-C CROSS-COUPLING REACTIONS C-C Cross-Coupling Reactions - An Indispensable Tool for the Synthesis of Complex Organic Molecules Palladium Pincer Complexes as C-C Cross-Coupling Catalysts The Role of Palladium Pincer Complexes in Heck Reactions Computational Investigations on the Thermal Feasibility of PdII/PdIV Cycles of Palladium Pincer-Catalyzed Heck Reactions Theoretical Investigations on a Pincer-Catalyzed Negishi Cross-Coupling Reaction Concluding Remarks REACTIONS OF SQUARE-PLANAR d8 PINCER COMPLEXES WITH OXYGEN AN HYDROGEN Introduction Insertion of Molecular Oxygen into Late-Transition Metal Hydride Bonds Hydrogenolysis of Late-Transition Metal Hydroxide and Alkoxide Complexes Summary Index

Catalytic Allylic C−H Acetoxylation and Benzoyloxylation via Suggested (η3-Allyl)palladium(IV) Intermediates

Palladium-catalyzed allylic acetoxylations and benzoyloxylations were carried out using iodonium salts. The reactions proceed under mild conditions with high regio- and stereoselectivity. The catalysis can be performed under both acidic and nonacidic conditions without use of BQ or other external oxidants and activator ligands. Deuterium labeling experiments clearly show that the catalytic reaction proceeds through (eta(3)-allyl)palladium intermediates. A stoichiometric study with one of the catalysts provided evidence for the formation of a Pd(IV) species.

Copper-Mediated Cyanotrifluoromethylation of Styrenes Using the Togni Reagent

Styrenes with an electron-deficient double bond undergo cyanotrifluoromethylation with a trifluoromethylated hypervalent iodine reagent in the presence of CuCN. The reaction proceeds under mild conditions in the presence of bulky phosphines or B2pin2 additives. The process is highly regioselective and involves the consecutive formation of two C-C bonds in a single addition reaction. In the presence of a p-methoxy substituent in the styrene, oxytrifluoromethylation occurs instead of the cyanotrifluoromethylation.

Selective C-H borylation of alkenes by palladium pincer complex catalyzed oxidative functionalization.

Selective C-H Borylation of Alkenes by Palladium Pincer Complex Catalyzed Oxidative Functionalization

Copper-mediated C–H trifluoromethylation of quinones

Quinones undergo copper-mediated C-H trifluoromethylation reactions using a hypervalent iodine reagent. The reactions have a broad synthetic scope involving naphtho, alkyl, chloro and methoxy quinones.

Trifluoromethylation of Propargylic Halides and Trifluoroacetates Using (Ph3P)3Cu(CF3) Reagent

A copper-mediated trifluoromethylation of propargylic halides and trifluoroacetates was performed with high allenyl or propargyl selectivity. The reaction proceeds smoothly with aliphatic and aromatic substituents bearing either electron-withdrawing or -supplying groups. Preliminary mechanistic results indicate an ionic mechanism involving nucleophilic transfer of the CF(3) group from the Cu complex to the propargylic substrate.

Pincer complex-catalyzed redox coupling of alkenes with iodonium salts via presumed palladium(IV) intermediates

Palladium pincer complexes directly catalyze the redox coupling reactions of functionalized alkenes and iodonium salts. The catalytic process, which is suitable for mild catalytic functionalization of allylic acetates and electron-rich alkenes, probably occurs through Pd(IV) intermediates. Due to the strong metal-ligand interactions, the oxidation of phosphine and amine ligands of the pincer complexes can be avoided in the presented reactions.

Mild Silver-Mediated Geminal Difluorination of Styrenes Using an Air- and Moisture-Stable Fluoroiodane Reagent†

An air- and moisture-stable fluoroiodane in the presence of AgBF4 is suitable for selective geminal difluorination of styrenes under mild reaction conditions. One of the C=F bonds is formed by transfer of electrophilic fluorine from the hypervalent iodine reagent, while the other one arises from the tetrafluoroborate counterion of silver. Deuterium-isotope-labelling experiments and rearrangement of methyl styrene substrates suggest that the reaction proceeds through a phenonium ion intermediate.

Palladium-Catalyzed Synthesis and Isolation of Functionalized Allylboronic Acids: Selective, Direct Allylboration of Ketones†

Textbook revision: allylboronic acids, which are easily prepared from allylic alcohols, react readily and selectively with ketones without Lewis acid catalysts.