Synlett

Synlett 2024; 35: A182-A198DOI: 10.1055/s-0043-1764003Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, GermanyArticle in Thieme eJournals:Table of contents

Manuel van Gemmeren was born in Madrid (Spain) and raised in both Spain and Germany. After studying chemistry at the Albert-Ludwigs University in Freiburg until 2010, he conducted his doctoral studies in the lab of Prof. Benjamin List and obtained his doctorate in 2014 (summa cum laude). Subsequently, he joined the group of Prof. Rubén Martín for postdoctoral studies. From 2016 onwards, he established his independent research group at the University of Münster. In 2022, he joined the Otto Diels Institute of Organic Chemistry at Kiel University as a tenured professor of organic chemistry. Research in the van Gemmeren lab focusses on the development of novel synthetic methods, typically based on Pd-catalyzed C–H activation, that enable challenging transformations to proceed with catalyst-controlled reactivity and selectivity.
Matthias Beller was born 1962 in Gudensberg (Germany) and studied chemistry at the University of Göttingen, Germany, where he completed his Ph.D. in 1989 in the group of Prof. L.-F. Tietze. As recipient of a Liebig scholarship, he subsequently spent one year studying with Prof. K. B. Sharpless at MIT, USA. From 1991 to 1995 he worked in industry. He then moved to the Technical University of München as a professor of inorganic chemistry. In 1998, he relocated to Rostock to head the Institute for Organic Catalysis, which in 2006 became the Leibniz Institute for Catalysis. The work of his group has been published in nearly 1150 original publications and reviews, and over 150 patent applications have been filed.

Carbonylation reactions serve as powerful tools to construct useful carbonyl compounds with high efficiency and atom economy. Compared with the well-developed carbonylation chemistry for alkenes, the dearomative carbonylation of arenes is largely underexplored, possibly owing to the severe challenge in overcoming resonance stabilization of arene π-systems. Bifunctional coordination to tricarbonylchromium not only offers a reliable strategy to activate inert benzene π-bonds towards dearomatizations but also provides the CO source for the carbonylation process. Herein, we highlight the recent progress in dearomative carbonylations of chromium-bound arenes through either the conventional nucleophile-electrophile addition mode or the newly-developed umpolung-enabled nucleophile-nucleophile addition mode under mild CO-gas-free conditions. Given the great abundance and diversity of arene substrates, we hope this review will attract more attention to this new direction of carbonylation chemistry.1 Introduction2 Dearomative Carbonylations of Arenes via Nucleophile-Electrophile Addition3 Dearomative Carbonylations of Arenes via Nucleophile-Nucleophile Addition4 Conclusion

Metal-catalyzed cross-coupling reactions have transformed molecular synthesis. Although metal-catalyzed reactions have been used for cross-electrophile coupling reactions, they remain challenging due to homodimer formation. Recently, our group developed an iron-catalyzed cross-electrophile coupling of benzyl halides and disulfides to produce thioethers without the use of an exogenous reductant or photoredox conditions, and with undetectable levels of elimination. This Synpacts article highlights both our design strategy to obviate detrimental homodimer formation and the generality of the method.1 Introduction2 Conceptualization and Development3 Mechanistic Studies and Hypothesis4 Conclusion and Future Directions

Transition-metal-catalyzed carbonylative transformations have been widely employed to convert CO gas into valuable carbonyl-containing molecules, mainly using noble metals (Pd, Rh, Ir, Ru) and more recently nickel and other catalysts. Although noble-metal catalysts have the advantage of reaction efficiency, their high-cost has led scientists to explore alternative procedures. Also under these backgrounds, we carried out some studies on nonexpensive metal-catalyzed carbonylative transformations. In this Account, we summarize the carbonylation reactions developed in our research group by using manganese and iron catalysis. These carbonylation reactions proceeded either via SET (single-electron transfer) or TET (two-electron transfer) mechanism.1 Introduction2 Manganese-Catalyzed Carbonylation of Alkyl Chlorides3 Manganese-Catalyzed Carbonylation of Alkyl Iodides4 Iron/Copper-Catalyzed Carbonylation of Alkyl Bromides5 Iron-Catalyzed Carbonylation of Alkyl Bromides6 Iron-Catalyzed Carbonylation of Alkyl-Boronic Pinacol7 Iron-Catalyzed Aminoalkylative Carbonylative Cyclization of Alkenes8 Conclusion and Outlook

Over decades, Cope rearrangements have attracted significant research interest in the field of synthetic organic chemistry relying on their ability to undergo stereoselective structural reorganization. Despite substantial progress, the development of this field remained confined to the use of parent 1,5-hexadienes. Against the backdrop of classical Cope reaction, we report the utilization of unconventional 1,6-heptadienes to develop the arylative Cope rearrangement by harnessing the interplay between the π-activation and cross-coupling reactivity mode of gold complexes. Several mechanistic investigations such as 31P NMR study, HRMS analysis, cross-over experiment, control experiments were performed to support the proposed cyclization-induced [3,3]-rearrangement mechanism in arylative Cope reaction.1 Gold-Catalyzed Cope Rearrangements2 Gold-Catalyzed Arylative Cope Rearrangement3 Conclusion

We describe a simple and efficient method for the synthesis of various benzoselenazoles and benzothiazoles by the Ullman coupling reaction of dihalobenzenes with acyl iso(seleno/thio)cyanate–malononitrile adducts in the presence of a copper catalyst with K2CO3 as a base at room temperature, without the help of additional ligands. Notable features of this protocol include the use of mild copper-catalyzed reaction conditions, simple and readily available raw materials, easy purification with the help of a solvent, and the synthesis of 17 new benzoselenazole and benzothiazole compounds.

Due to an inherent polarity mismatch of the corresponding retrosynthetic synthons, 1,4-dicarbonyl synthesis through polar pathways requires a retrosynthetic rethink. While umpolung-based approaches exist, efficient control of both the absolute and relative configuration of newly formed stereogenic centres within this motif has long proven particularly challenging. In this Synpact article, we highlight our work on the stereodivergent synthesis of 1,4-dicarbonyl compounds through an unusual transformation that relies on vinyl sulfoxides and ynamides as reactants. This method allows stereoselective access to each and every one out of the four possible stereoisomers of a generic 1,4-dicarbonyl target in a process where enantio- and diastereoselectivity are ‘dialled into’ the vinyl sulfoxide partner. Recent studies show that the thus formed 1,4-dicarbonyls serve as excellent linchpins for structural diversification into highly substituted heterocycles, including those found in natural products.1 Introduction2 [3,3]-Sigmatropic Rearrangement of Ynamides and Vinyl Sulfoxides under Acid Catalysis3 Cyclisation towards γ-Lactones and γ-Lactams4 Application in Total Synthesis5 Conclusion

Allylic ethers are a common occurrence in natural products, and are often used as intermediates in target-oriented synthesis. Their synthesis often relies on the use of transition-metal catalysts. Here, we report an organocatalytic method for the allylation of O-centered nucleophiles, the Lewis base catalyzed allylation of silyl ethers with allylic fluorides. The method relies on the concept of latent pronucleophiles in Lewis base catalysis to overcome common limitations in substrate scope, even permitting the allylation of sterically congested O-pronucleophiles. When chiral Lewis base catalysts are used, the allyl ethers are produced in an enantioenriched form through kinetic resolution of fluorides, where the stereoselectivity is determined by the chiral catalyst.

Spirocyclobutanes have gained significant attention in medicinal chemistry discovery programs due to their broad spectrum of biological activities and clinical applications. Utilizing ring strain in small molecules to drive organic transformations is one of the most powerful tools in chemical synthesis. Our research group has focused on developing new synthetic strategies enabled by ring strain to construct complex molecules selectively and efficiently. This account summarizes our recent efforts toward the synthesis of a library of functionalized spirocyclobutanes by harnessing the ring strain of bicyclo[1.1.0]butanes. Three spicrocyclization cascades have been developed to incorporate a diverse range of radical precursors into spirocycobutanes.1 Introduction2 Synthesis of Spirocyclobutyl Lactones and -Lactams using Bifunctional Reagents3 Dual Photoredox/Nickel Catalysis for the Synthesis of Spirocyclobutyl Lactams4 Synthesis of Spirocyclobutyl Oxindoles under Photoredox Catalysis5 DFT Studies6 Conclusion