Article
Chemistry, Organic
Fanni Bede, Laszlo Kollar, Nandor Lambert, Peter Huszthy, Peter Pongracz
Summary: Palladium-catalyzed hydroaminocarbonylation reactions of olefins using aliphatic amines were successfully performed under carbon monoxide atmosphere. The targeted amides were synthesized in moderate to good isolated yields without the need for acidic additives. The effect of chiral diphosphines on product distribution, including chemo-, regio-, and enantioselectivities, was also investigated.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Biochemistry & Molecular Biology
Nuray Uzunlu, Peter Pongracz, Laszlo Kollar, Attila Takacs
Summary: In this research, bio-derived hemicellulose-based solvents, namely ethyl levulinate, methyl levulinate, and 2-methyltetrahydrofuran, were used as green alternatives in palladium-catalyzed aminocarbonylation reactions. Optimization reactions were conducted using iodobenzene and morpholine under varying conditions, including temperature, pressure, and ligands. The study found that the XantPhos ligand significantly influenced the conversion (98%) and chemoselectivity (100% carboxamide) compared to the monodentate PPh3 ligand. Furthermore, the optimized conditions were applied to expand the range of substrates and amine nucleophiles.
Article
Chemistry, Applied
Seoyoung Lee, Juyeong Kim, Kyungjun Kang, Ansoo Lee, Hyunwoo Kim
Summary: In this study, we developed a ligand-controlled palladium-catalyzed allylic substitution approach that selectively achieves [1+1] and [1+2] allylic aminations between allylic diols and diamines. By combining this approach with sequential acetylation and allylic amination, tetraazamacrocycles with ring sizes ranging from 16 to 38 were successfully synthesized. These findings demonstrate the potential of a sequential allylation strategy for synthesizing complex molecules with broad applications in the fields of chemistry, pharmaceuticals, and medicine.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Organic
Yusuke Kuroda
Summary: This study introduces a novel strategy for the [1,3]-rearrangement of imidates based on the oxidative addition of a palladium(0) catalyst, enabling the synthesis of structurally distinct allylic amides under mild and base-free conditions.
Article
Chemistry, Physical
Caitlin Kozack, Stephen J. Tereniak, Jonathan N. Jaworski, Bao Li, David L. Bruns, Spring M. M. Knapp, Clark R. Landis, Shannon S. Stahl
Summary: This study focuses on the impact of benzoquinone on the catalytic activity in palladium(II)-catalyzed allylic acetoxylation. The results indicate that benzoquinone enhances the performance of the catalyst, showing a synergistic effect with Co(salophen) in improving reaction performance. The mechanistic studies suggest that both benzoquinone and oxygen play significant roles in oxidizing Pd(0) to Pd(II), leading to better reaction outcomes.
Article
Chemistry, Multidisciplinary
Xin Yu, Lingfei Hu, Wolfgang Frey, Gang Lu, Rene Peters
Summary: Catalytic allylic substitution is an important method in asymmetric synthesis to generate C-C bonds with enantioselectivity. However, a common limitation is the formation of allylic substitution products with (E)-configured C=C double bonds. In this study, a planar chiral palladacycle catalyst was used to achieve a diastereospecific reaction outcome, maintaining the C=C double bond geometry of the allylic substrates in highly enantioenriched products.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Jeanne Masson-Makdissi, Justin Ching, Cian M. Reid, Mark Lautens
Summary: A dual metal approach enables the use of unsymmetrical diallyl carbonates as viable enolate precursors for allylic alkylation reactions, allowing facile access to various alpha-quaternary allylated aldehydes and ketones. This methodology involves regioselective Pd-catalyzed decarboxylative oxidative addition and Rh-catalyzed isomerization.
Article
Chemistry, Multidisciplinary
James E. Baumann, Gojko Lalic
Summary: A new method for the differential dihydrofunctionalization of terminal alkynes has been developed, enabling the synthesis of allylic boronate esters through a reductive three-component coupling reaction. This transformation, promoted by a copper/palladium catalyst system, hydrofunctionalizes both pi-bonds of the alkyne. The method is compatible with a wide range of functional groups.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Simon Sieger, Ilja Lubins, Bernhard Breit
Summary: A highly versatile palladium-catalyzed allylation reaction has been reported, providing a waste-free access to allylated nucleophiles with unlimited possibilities for further functionalization. The reaction can be conducted using propadiene in toluene, and the mechanism is supported by deuterium labeling experiments.
Article
Chemistry, Physical
Simon V. Sieger, Ilja Lubins, Bernhard Breit
Summary: A highly versatile palladium-catalyzed allylation reaction using various pronucleophiles has been reported. Through the use of propadiene in toluene, this reaction provides an efficient and waste-free method to obtain allylated nucleophiles with unlimited potential for further functionalization. The Pd/BINAP system is not only capable of adding N-, O-, and S-pronucleophiles, but also C-pronucleophiles to allene. The plausible mechanism is supported by deuterium labeling experiments.
Article
Chemistry, Multidisciplinary
Jeanne Masson-Makdissi, Liher Prieto, Xavier Abel-Snape, Mark Lautens
Summary: This study demonstrates the feasibility and advantages of combining two distinct asymmetric transition-metal-catalyzed reactions in one pot, effectively converting simple allyl enol carbonate precursors into enantioenriched cyclic ketones. Despite the challenges in controlling stereoselectivity, the products are obtained with high enantiomeric excesses exceeding 99% ee, surpassing those obtained from individual reactions. Additionally, the one-pot reaction is enantio- and diastereodivergent, allowing easy access to all stereoisomers from the same starting materials.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Pierre-Louis Lagueux-Tremblay, Celestin Augereau, Pranav Nair, Kwan Ming Tam, Bruce A. Arndtsen
Summary: The use of metal catalysis to form potent acylating agents is an important approach to expand the application of carbonylation reactions. However, the reductive elimination of these reactive products has been a challenge, making these reactions often high temperature, high pressure, and limited in scope. In this study, a mild and versatile palladium catalyzed carbonylative method was developed to generate electrophilic acyl-DMAP salts by exploiting the counterion. The weakly coordinating triflate anion was found to destabilize Pd(II) and enable irreversible reductive elimination, while ligand design facilitated the rapid activation of aryl or vinyl triflates. This approach allows palladium catalyzed carbonylations to be carried out under exceptionally mild conditions, with low catalyst loading and using readily available C(sp2)-triflate reagents.
Article
Chemistry, Physical
Pierre-Louis Lagueux-Tremblay, Celestin Augereau, Pranav Nair, Kwan Ming Tam, Bruce A. Arndtsen
Summary: The use of metal catalysis to form potent acylating agents is an important method to broaden the applicability of carbonylation reactions. However, the reductive elimination of these reactive products has presented a challenge, making the reactions often high temperature and high pressure, and limited in scope. In this study, a mild and versatile palladium catalyzed carbonylative method was developed to generate electrophilic acyl-DMAP salts. The use of triflate anion as a counterion destabilizes Pd(II) and allows for irreversible reductive elimination, while ligand design enables the rapid activation of aryl or vinyl triflates.
Article
Chemistry, Multidisciplinary
Pu-Sheng Wang, Liu-Zhu Gong
Summary: Pd-catalyzed asymmetric allylic C-H functionalization is a powerful tool to access chiral and densely functionalized molecules from easily accessible alkenes, resulting in increased step- or atom-economy by minimizing functional group manipulations. However, due to inadequate stereoselection strategies, this field is still in its early stage. This essay describes the journey to identify asymmetric catalytic systems, the mechanism of allylic C-H activation, control of stereo- and regioselectivity, and applications in asymmetric synthesis.
CHINESE JOURNAL OF CHEMISTRY
(2023)
Review
Chemistry, Multidisciplinary
Xi Wang, Youbin Peng, Ling Zhao, Xiaohong Huo, Wanbin Zhang
Summary: Compared to the stereocontrol of the stereocenter at the allyl unit, asymmetric induction of prochiral nucleophiles is a challenging task in Pd-catalyzed asymmetric allylic substitutions due to the remote distance between the chiral catalyst and the prochiral nucleophile. Extensive efforts have been made to address this challenge through the design of chiral ligands. Recently, synergistic catalysis, including bimetallic catalysis and Pd/organocatalysis, has gained attention for its potential advantages in improving reactivity and selectivity, and providing a simple and unified method for the stereocontrol of prochiral nucleophiles. This review summarizes the history and advances in this field.
SCIENCE CHINA-CHEMISTRY
(2023)
