Article
Chemistry, Organic
Christian J. Rugen, Manuel Alcarazo
Summary: Alpha-cationic phosphines are phosphine compounds with at least one positively charged cyclic substituent directly attached to the phosphorus atom, exhibiting significantly diminished donor properties. They can increase the electrophilicity at metal centers in certain catalytic cycles, leading to enhanced reactivity. Easy synthesis, stability, and a ligand acceleration effect make alpha-cationic phosphines useful tools for synthetic practitioners.
Article
Chemistry, Multidisciplinary
Rui Wei, Shaoying Ju, Liu Leo Liu
Summary: We report a facile and highly modular access to an intriguing class of free Au-substituted phosphines (AuPhos). Au-substitution can boost the electron-releasing ability of AuPhos, leading to an electronically and sterically tunable, extremely electron-rich phosphorus center. Multi-nuclear transition metal complexes ligated by AuPhos are readily prepared, and preliminary catalytic results show the facilitation of C-N coupling reactions and decarbonylation reactions. This work provides insights for future development of electron-rich ligands.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Julia E. Borowski, Samuel H. Newman-Stonebraker, Abigail G. Doyle
Summary: A comparison study of mono- and bisphosphine ligands in Ni-catalyzed Suzuki-Miyaura cross-coupling reactions revealed that monophosphines exhibit higher reactivity, particularly with electronically deactivated and sterically hindered substrates. Mechanistic experiments showed that monoligated (P1Ni) species accelerate the organometallic steps of the catalytic cycle, while bisligated (P2Ni) species prevent off-cycle reactions and catalyst poisoning by heterocyclic motifs. These findings provide guidelines for ligand selection against challenging substrates and future ligand design tailored to the mechanistic demands of Ni-catalyzed cross-coupling reactions.
Article
Chemistry, Multidisciplinary
Hao Deng, Marco Bengsch, Nico Tchorz, Constanze N. Neumann
Summary: This article introduces a novel method for fine-tuning phosphine ligands, which enables diversification of phosphine compounds by introducing different substituents into previously inaccessible positions. Compared to existing methods, this approach overcomes the limitations of phosphorus-directed reactions.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Heidar Darmandeh, Julian Loeffler, Nikolaos V. Tzouras, Busra Dereli, Thorsten Scherpf, Kai-Stephan Feichtner, Sofie Vanden Broeck, Kristof Van Hecke, Marina Saab, Catherine S. J. Cazin, Luigi Cavallo, Steven P. Nolan, Viktoria H. Gessner
Summary: Studies show that Au...H-C hydrogen bonds can replace arene-gold interactions without affecting the catalytic performance of gold catalysts. The C-H moiety next to the onium center forms the strongest interaction with Au...H-C hydrogen bonds. These findings support Au...H-C hydrogen bonds as fundamental secondary interactions in gold catalysts.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Jan Schulz, Reike Clauss, Aleksandr Kazimir, Sieglinde Holzknecht, Evamarie Hey-Hawkins
Summary: The synthesis of B9-Phos ligands with two carboranyl moieties and bulky electron-donating substituents, previously deemed unattainable, is reported. The electrochemical properties of B9-Phos ligands were investigated, showing the ability of mesityl derivatives to form stabilized phosphoniumyl radical cations. The B9-Phos ligands possess a highly electron-releasing character surpassing that of alkyl phosphines and commonly used N-heterocyclic carbenes.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Jens Handelmann, Chatla Naga Babu, Henning Steinert, Christopher Schwarz, Thorsten Scherpf, Alexander Kroll, Viktoria H. Gessner
Summary: By studying the impact of substituents in ylide-substituted phosphines, it was found that introducing bulky aryl groups with ortho-substituents can significantly enhance the catalytic activity of gold complexes in reactions, not due to increased steric demand, but because of steric protection of the reactive ylidic carbon center. The designed mesityl-substituted YPhos ligand showed high catalyst stability and achieved high turnover numbers in various reactions.
Article
Chemistry, Organic
Guang-Da Xia, Zi-Kui Liu, Yu-Lian Zhao, Feng-Cheng Jia, Xiao-Qiang Hu
Summary: The synthesis of tertiary phosphines(III) has been a long-standing challenge in synthetic chemistry due to issues including harsh conditions, sensitive organometallic reagents, and pre-functionalized substrates. In this study, a strategically novel C(sp(3))-H bond phosphorylation method is reported, which allows for the synthesis of structurally diverse tertiary phosphines(III) from industrial phosphine(III) sources under mild photocatalytic conditions. The combination of ligand-to-metal charge transfer (LMCT) and hydrogen atom-transfer (HAT) process enables the generation of alkyl radicals from hydrocarbons. Furthermore, this catalytic system can also be applied for the polymerization of electron-deficient alkenes.
Review
Chemistry, Applied
Pawan Kumar, Urvashi Sharma, Guddekoppa S. Ananthnag
Summary: This article provides a detailed overview of the synthesis, reactivity, structural features, and catalytic activities of acyl phosphines and bis(acyl) phosphines reported in the last three decades. Although acyl phosphines have been known historically, their literature is not exhaustive due to the vulnerability of P-C(O) bonds toward nucleophilic substitution reactions. However, there has been a renewed interest in the synthesis of acyl phosphines and di(acyl) phosphines recently, with the examples of phosphines possessing two acyl groups found more frequently in the literature. Transition-metal complexes of acyl phosphines and di(acyl) phosphines have been moderately explored, but their catalytic applications are limited.
APPLIED ORGANOMETALLIC CHEMISTRY
(2022)
Article
Polymer Science
Pei Li, Hongju Liu, Wanlu Tian, Zhanshan Ma, Xiaoyue Wang, Guoyong Xu, Chao Li, Muhammad Qasim, Fuzhou Wang
Summary: Improvement of amide derived catalysts used in olefin polymerization was achieved by synthesizing cationic nickel catalysts with steric and electronic factors variation. These bulky nickel catalysts showed significantly higher activity and thermal stability compared to previous open pyridine carboxamidate nickel catalysts. They produced higher molecular weight semi-crystalline polyethylene with tunable branching densities and melting points. Additionally, they also promoted the copolymerization of ethylene and methyl 10-undecenoate to yield functionalized polyethylenes with high incorporation rate of MU.
Review
Chemistry, Physical
Bryan T. Novas, Rory Waterman
Summary: Organophosphines have attracted attention in various fields, from agriculture to fine chemicals. Hydrophosphination is an efficient method for selectively preparing P-C bonds, maximizing the efficient use of phosphorus. This review provides a comprehensive guide to known catalysts, highlighting advancements in unique substrates and selectivity.
Article
Chemistry, Inorganic & Nuclear
Ivan Cortes, Jorge Juan Cabrera-Trujillo, Israel Fernandez
Summary: The physical factors behind the high activity of gold(i)-catalysts with alpha-cationic phosphole ligands have been computationally explored. It was found that the cationic phosphole ligands induce changes in the geometry and electronic structure of the initial pi-complex, significantly enhancing its electrophilicity, leading to an enhancement of the molecular orbital interaction responsible for the activating effect of these cationic ligands.
DALTON TRANSACTIONS
(2021)
Article
Chemistry, Multidisciplinary
Yanyan Zhang, Yunhong Han, Shengqing Zhu, Feng-Ling Qing, Xiao-Song Xue, Lingling Chu
Summary: This article describes a photochemically induced selective and divergent cyanation reaction of alkynes, enabled by phosphorus radicals. By using simple triarylphosphine as a co-catalyst, three cyanation reactions, including di-hydrocyanation, anti-Markovnikov hydrocyanation, and domino hydrocyanation/reduction, can be achieved, resulting in a wide array of alkyl dinitriles, alkenyl nitriles, and alkyl nitriles under mild conditions. Terminal and internal alkynes show high efficiency and excellent selectivity. Synthetic applications for biologically active agents and preliminary experimental and computational mechanistic studies are reported.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Yun Ye, Jie Zhu, Haijiao Xie, Yinhua Huang
Summary: A ligand-controlled rhodium-catalyzed reaction has been reported, which allows the synthesis of different structures of alkene products in a switchable manner.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Applied
Dibya Yadav, Shilpi Misra, Dheeraj Kumar, Suryabhan Singh, Amrendra K. Singh
Summary: The application of cationic ruthenium pincer complexes in transfer hydrogenation reactions of ketones was studied, with in situ transformations observed during synthesis helping propose a plausible mechanism via the hydride complex 3b. All complexes are efficient catalyst precursors for the transfer hydrogenation of ketones.
APPLIED ORGANOMETALLIC CHEMISTRY
(2021)
