Aktive Anode auf Molybdänbasis für dehydrierende Kupplungen

Thieme Chemistry Journals Awardees – Where Are They Now? Molybdenum(V)-Mediated Synthesis of Nonsymmetric Diaryl and Aryl Alkyl Chalcogenides

Oxidative chalcogenation reaction using molybdenum(V) reagents provides fast access to a wide range of nonsymmetric aryl sulfides and selenides. The established protocol is tolerated by a variety of labile functions, protecting groups, and aromatic heterocycles. In particular, when labile moieties are present, the use of molybdenum(V) reagents provides superior yields compared to other oxidants.

Modular Approach to 9-Monosubstituted Fluorene Derivatives Using Mo(V) Reagents.

Oxidative coupling using molybdenum(V) reagents provides fast access to highly functionalized 9-monosubstituted fluorenes. This synthetic approach is highly modular, is high yielding, and tolerates a variety of labile moieties, e.g. amides or iodo groups. The established protocol leads to promising precursors for pharmacologically important analogues of melatonin.

Überoxidation als Schlüsselschritt im Mechanismus der MoCl5 - vermittelten dehydrierenden Arenkupplung

Over-Oxidation as the Key Step in the Mechanism of the MoCl5-Mediated Dehydrogenative Coupling of Arenes.

Molybdenum pentachloride is an unusually powerful reagent for the dehydrogenative coupling of arenes. Owing to the high reaction rate using MoCl5, several labile moieties are tolerated in this transformation. The mechanistic course of the reaction was controversially discussed although indications for a single electron transfer as the initial step were found recently. Herein, based on a combined study including synthetic investigations, electrochemical measurements, EPR spectroscopy, DFT calculations, and mass spectrometry, we deduct a highly consistent mechanistic scenario: MoCl5 acts as a one-electron oxidant in the absence of TiCl4 and as two-electron oxidant in the presence of TiCl4, bu…

ChemInform Abstract: Modular Approach to 9-Monosubstituted Fluorene Derivatives Using MoVReagents.

Investigations on isomerization and rearrangement of polycyclic arenes under oxidative conditions – Anodic versus reagent-mediated reactions

Abstract Electro-organic conversions at an active molybdenum anode enable the formation of fused arenes. High chemoselectivity was achieved under anodic conditions, and a reagent-induced selectivity was observed by comparison with results of MoCl5-mediated reactions. Polycyclic arenes like phenanthrenes, triphenylenes, chrysenes, or helicenes were selectively obtained in yields up to 87% and in some cases unusual rearrangements were crucial for the product formation.

Mild, Fast, and Easy To Conduct MoCl5-Mediated Dehydrogenative Coupling Reactions in Flow

A convenient and straightforward approach to performing oxidative coupling reactions in flow is presented. A collection of electron-rich benzene derivatives was subjected to this protocol, and the distinct utility of molybdenum pentachloride (MoCl5) is established. Using this unexplored protocol, biphenyls could be obtained in 21–91% isolated yield. This simple protocol opens a new chapter in reagent-mediated dehydrogenative coupling reactions, and yields are compared to classical approaches.

Mo-Based Oxidizers as Powerful Tools for the Synthesis of Thia- and Selenaheterocycles.

A highly efficient synthetic protocol for the synthesis of thia- and selenaheterocycles has been developed. By employing a MoCl5 -mediated intramolecular dehydrogenative coupling reaction, a broad variety of structural motifs was isolated in yields up to 94 %. The electrophilic key transformation is tolerated by several labile moieties like halides and tertiary alkyl groups. Due to the use of disulfide or diselenide precursors, a high atom efficiency was achieved.

Active Molybdenum‐Based Anode for Dehydrogenative Coupling Reactions

A new and powerful active anode system that can be operated in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) has been discovered. In HFIP the molybdenum anode forms a compact, conductive, and electroactive layer of higher-valent molybdenum species. This system can replace powerful but stoichiometrically required MoV reagents for the dehydrogenative coupling of aryls. This electrolytic reaction is more sustainable and allows the conversion of a broad scope of activated arenes.

CCDC 1520081: Experimental Crystal Structure Determination

Related Article: Peter Franzmann, Sebastian B. Beil, Peter M. Winterscheid, Dieter Schollmeyer, Siegfried R. Waldvogel|2017|Synlett|28|957|doi:10.1055/s-0036-1588140

CCDC 1520080: Experimental Crystal Structure Determination

Related Article: Peter Franzmann, Sebastian B. Beil, Peter M. Winterscheid, Dieter Schollmeyer, Siegfried R. Waldvogel|2017|Synlett|28|957|doi:10.1055/s-0036-1588140

CCDC 1882077: Experimental Crystal Structure Determination

Related Article: Sebastian B. Beil, Peter Franzmann, Timo Müller, Maximilian M. Hielscher, Tobias Prenzel, Dennis Pollok, Nicole Beiser, Dieter Schollmeyer, Siegfried R. Waldvogel|2018|Electrochimica Acta|302|310|doi:10.1016/j.electacta.2019.02.041

CCDC 1520078: Experimental Crystal Structure Determination

Related Article: Peter Franzmann, Sebastian B. Beil, Peter M. Winterscheid, Dieter Schollmeyer, Siegfried R. Waldvogel|2017|Synlett|28|957|doi:10.1055/s-0036-1588140

CCDC 1520082: Experimental Crystal Structure Determination

Related Article: Peter Franzmann, Sebastian B. Beil, Peter M. Winterscheid, Dieter Schollmeyer, Siegfried R. Waldvogel|2017|Synlett|28|957|doi:10.1055/s-0036-1588140

CCDC 1872281: Experimental Crystal Structure Determination

Related Article: Peter Franzmann, Sebastian B. Beil, Dieter Schollmeyer, Siegfried R. Waldvogel|2019|Chem.-Eur.J.|25|1936|doi:10.1002/chem.201805938

CCDC 1882075: Experimental Crystal Structure Determination

Related Article: Sebastian B. Beil, Peter Franzmann, Timo Müller, Maximilian M. Hielscher, Tobias Prenzel, Dennis Pollok, Nicole Beiser, Dieter Schollmeyer, Siegfried R. Waldvogel|2018|Electrochimica Acta|302|310|doi:10.1016/j.electacta.2019.02.041

CCDC 1882076: Experimental Crystal Structure Determination

Related Article: Sebastian B. Beil, Peter Franzmann, Timo Müller, Maximilian M. Hielscher, Tobias Prenzel, Dennis Pollok, Nicole Beiser, Dieter Schollmeyer, Siegfried R. Waldvogel|2018|Electrochimica Acta|302|310|doi:10.1016/j.electacta.2019.02.041

CCDC 1882073: Experimental Crystal Structure Determination

Related Article: Sebastian B. Beil, Peter Franzmann, Timo Müller, Maximilian M. Hielscher, Tobias Prenzel, Dennis Pollok, Nicole Beiser, Dieter Schollmeyer, Siegfried R. Waldvogel|2018|Electrochimica Acta|302|310|doi:10.1016/j.electacta.2019.02.041

CCDC 1882074: Experimental Crystal Structure Determination

Related Article: Sebastian B. Beil, Peter Franzmann, Timo Müller, Maximilian M. Hielscher, Tobias Prenzel, Dennis Pollok, Nicole Beiser, Dieter Schollmeyer, Siegfried R. Waldvogel|2018|Electrochimica Acta|302|310|doi:10.1016/j.electacta.2019.02.041

CCDC 1520079: Experimental Crystal Structure Determination

Related Article: Peter Franzmann, Sebastian B. Beil, Peter M. Winterscheid, Dieter Schollmeyer, Siegfried R. Waldvogel|2017|Synlett|28|957|doi:10.1055/s-0036-1588140

CCDC 1872280: Experimental Crystal Structure Determination

Related Article: Peter Franzmann, Sebastian B. Beil, Dieter Schollmeyer, Siegfried R. Waldvogel|2019|Chem.-Eur.J.|25|1936|doi:10.1002/chem.201805938

CCDC 1882078: Experimental Crystal Structure Determination

Related Article: Sebastian B. Beil, Peter Franzmann, Timo Müller, Maximilian M. Hielscher, Tobias Prenzel, Dennis Pollok, Nicole Beiser, Dieter Schollmeyer, Siegfried R. Waldvogel|2018|Electrochimica Acta|302|310|doi:10.1016/j.electacta.2019.02.041