Article
Chemistry, Multidisciplinary
Nurbey Gulia, Jaroslaw Fornalski, Adrianna Gumienna, Malgorzata Ambroziak, Slawomir Szafert
Summary: This study reports a method of palladium-catalyzed C-H arylation assisted with a 3,4,4-trimethylpyrazol-5-on directing group, which selectively provides mono- and di-ortho-arylated products. The steric hindrance between the directing group and the already introduced aryl substituent enables control of mono- vs. diarylation selectivity by the reaction temperature. A series of monosubstituted and disubstituted derivatives were obtained in good yields. In addition, a one-pot procedure for unsymmetrical double-arylation to give corresponding products was developed, and the synthesis and X-ray study of intermediate palladium metallacycles were conducted. The decarboxylative cleavage of the pyrazolone directing group under mild conditions gave synthetically useful hydrazones. Overall, this solution provides an alternative synthetic pathway for ortho arylated derivatives of arylhydrazines.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Jun-Jie Tian, Rui-Rui Li, Gui-Xiu Tian, Xiao-Chen Wang
Summary: Here, we describe a new method for enantioselective C-H allylation of pyridines at C3 using a tandem borane and palladium catalysis. This method involves borane-catalyzed pyridine hydroboration, palladium-catalyzed enantioselective allylation of the resulting dihydropyridines with allylic esters, and air oxidation to afford the products. This method allows for the introduction of an allylic group at C3 with excellent regio- and enantioselectivities.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Rie Yoshimoto, Attila Taborosi, Qiyuan He, Yusuke Ano, Naoto Chatani, Seiji Mori
Summary: The reaction between aromatic amides and maleimides, catalyzed by palladium, leads to the formation of a product with double C-H bond activation, occurring at both the benzylic and meta positions. Computational chemistry studies reveal a stepwise mechanism involving a six-membered palladacycle, maleimide insertion, protonation of the Pd-N bond, and activation of the meta C-H bond. The site selectivity is determined by the interaction energy controlling the insertion of maleimide into the Pd-C(sp(3)) bond. The meta C-H bond activation step is identified as the rate-determining step based on the energetic span model. The 2-thiomethylphenyl group is found to function effectively as a directing group due to strong Pd-S bonding and the destabilizing effect of the deformation energy.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
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.
Review
Chemistry, Applied
Oleg Y. Lyakin, Dmitry S. Bushmin, Evgenii P. Talsi, Konstantin P. Bryliakov
Summary: This review summarizes the recent advances in homogeneous oxidation of hydrocarbon C(sp(3))-H bonds catalyzed by nickel and palladium complexes, and discusses the correlations between the catalyst structure, ligand properties, catalytic conditions, and catalytic reactivity (efficiency, chemoselectivity, and regioselectivity).
APPLIED ORGANOMETALLIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Ji Liu, Edward M. Laguna, Arun Raj Kizhakkayil Mangadan, Kyoungmin Kang, Aaron Aponick
Summary: A simple procedure for intermolecular enantioselective palladium-catalyzed decarboxylative allylation of beta-ketoacids is described. The method uses allyl carbonates as coupling substrates and allows direct access to alpha-allylated ketones with newly formed quaternary stereocenters. Experimental results suggest the transformation proceeds via an inner-sphere mechanism rather than the traditional outer-sphere process, and the reaction demonstrates potential usefulness in the enantioselective synthesis of (+)-adalinine.
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)
Article
Chemistry, Multidisciplinary
Kai Liu, Tingrui Li, Duan-Yang Liu, Weipeng Li, Jian Han, Chengjian Zhu, Jin Xie
Summary: This study reports an unprecedented C-H bond functionalization of cyclopropenes enabled by dinuclear gold catalysis, resulting in highly selective C-H allylation, alkynylation, and halogenation reactions with organic halides. The reaction does not require strong external oxidants and affords access to functionalized cyclopropenes in moderate to good yields. The reductive elimination process for construct C-C or C-X bonds can be controlled by using different dinuclear gold catalysts.
SCIENCE CHINA-CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Rui Yan, Hang Yu, Zhong-Xia Wang
Summary: The study found that [Cp*Co(CO)I-2] effectively catalyzes the pyridyl-directed C-H allylation of arenes with allylic amines in the presence of AgOAc and CF3COOAg, resulting in moderate to high yields under appropriate conditions. The reaction shows good tolerance towards a variety of functional groups and has certain universality for catalyzing the arylation of C-H bonds.
CHINESE JOURNAL OF CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Xiao-Yun Ruan, Tao Zhang, Wen-Ao Li, Yi-Zhuo Yin, Zhi-Yong Han, Liu-Zhu Gong
Summary: In this study, a photoinduced palladium-catalyzed hydrogen atom transfer triggered 1,2-difunctionalization of conjugated dienes was reported, achieving remote functionalization and selective difunctionalization to synthesize highly diverse amides.
SCIENCE CHINA-CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Alexandra M. Zima, Oleg Y. Lyakin, Anna A. Bryliakova, Dmitrii E. Babushkin, Konstantin P. Bryliakov, Evgenii P. Talsi
Summary: Catalytic approaches to late-stage creation of new C-O bonds, especially via oxygenation of particular C-H groups in complex organic molecules, provide challenging tools for the synthesis of biologically active compounds and candidate drugs. The key role of the oxygen-transferring high-valent iron-oxygen species in selective oxygenation is now well established. In this Personal Account, recent data on the reactivity of bioinspired formally oxoiron(V) catalytically active sites toward organic substrates having C=C and C(sp(3))-H groups are analyzed, with a focus on the factors governing the oxidation chemo- and stereoselectivity.
Article
Chemistry, Physical
Roushan Prakash Singh, Soumen Sinhababu, Neal P. Mankad
Summary: This Perspective reviews recent advances and applications of Al/M heterobimetallic catalysis in various areas, including polymerization, epoxide activation and carbonylation. The mechanistic role of the aluminum site is highlighted, and a comprehensive perspective is constructed by including a broad range of Al-containing metalloligands and Al/M combinations.
Article
Chemistry, Multidisciplinary
Rui Liu, Meng-Lan Shen, Lian-Feng Fan, Xiao-Le Zhou, Pu-Sheng Wang, Liu-Zhu Gong
Summary: Allylamines are important for synthesizing bioactive compounds and can be obtained through the palladium-catalyzed allylic C-H amination of 1,4-dienes. This reaction favors the formation of thermodynamically unstable Z-allylamines with aromatic amines. Aliphatic cyclic amines can also participate, but linear dienyl allylic amines are the main products.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Santosh Kumar Keshri, Suchithra Madhavan, Manmohan Kapur
Summary: Transition-metal catalysis has revolutionized organic synthesis by enabling efficient C-C and C-heteroatom bond formation. To functionalize nonbiased C-H bonds, various strategies have been developed, including the use of directing groups and substrate modification.
Article
Chemistry, Organic
Davide Illuminati, Anna Fantinati, Tiziano De Ventura, Daniela Perrone, Chiara Sturaro, Valentina Albanese, Erika Marzola, Virginia Cristofori, Julie Oble, Giovanni Poli, Claudio Trapella
Summary: A small library of NH-Boc- or NH-Fmoc-protected L-phenylalanines carrying methyl groups at positions 2 and 6 and diverse functionalities at position 4 has been synthesized through a Pd-catalyzed directed C-H dimethylation. The electronic and steric properties of the resulting amino acid derivatives can be altered by appending a variety of electron-withdrawing, electron-donating, or bulky groups.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Camilla Loro, Julie Oble, Francesca Foschi, Marta Papis, Egle M. Beccalli, Sabrina Giofre, Giovanni Poli, Gianluigi Broggini
Summary: Treatment of O-allyl N-tosyl carbamates with aromatic compounds in the presence of Cu(OTf)(2) or TMSOTf as promoters results in the formation of N-substituted 1-arylpropan-2-amines, 1,2-diarylpropanes, 1,1-diarylpropanes, or indanes, depending on the nature of the promoter and aryl substrates. A proposed mechanism explains the outcome of these C-H based cascades, involving initial acid promoted decarboxylative/deamidative Friedel-Crafts allylation followed by protonation of the allylated arene.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Organic
Roberto Sala, Gredy Kiala, Luis F. Veiros, Gianluigi Broggini, Giovanni Poli, Julie Oble
Summary: A method for the directed alkenylation of 2-carboxaldimine-heterocyclopentadienes using Ru3(CO)12 catalyst has been developed. This reaction enables coupling of various electron-poor alkenes with furan, pyrrole, indole, and thiophene 2-carboxaldimines, and does not require additional sacrificial oxidants. Mechanistic insights have been obtained through density functional theory calculations.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Sebastien Curpanen, Giovanni Poli, Alejandro Perez-Luna, Julie Oble
Summary: Here we report a directed catalytic reaction for furfuryl imines, which allows access to versatile synthetic platforms. The reaction utilizes imines as directing groups and trialkylsilanes or bis(trimethylsilyl)methylsilane as silylating agents, in the presence of a hydride scavenger. Subsequently, fluoride-mediated activation strategies are applied to achieve a wide range of transformations and obtain high yields of products.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Review
Chemistry, Organic
Alessia Mori, Sebastien Curpanen, Cristofer Pezzetta, Alejandro Perez-Luna, Giovanni Poli, Julie Oble
Summary: Furfural and related compounds, as building blocks of industrial interest, have gained attention as green alternatives to petroleum-derived compounds. This minireview summarizes the methods of direct C-H functionalization of furfurals without modifying the redox state of the aldehyde function, focusing on transition metal catalyzed functionalization of the heteroaromatic nucleus and C-H transformations of the aldehyde function.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Sebastien Curpanen, Per Reichert, Gabriele Lupidi, Giovanni Poli, Julie Oble, Alejandro Perez-Luna
Summary: 3-silylated furfurals are converted into 3-silylated 2-furyl carbinols upon condensation with organomagnesium or organolithium reagents. The hydroxy unit of the carbinol adducts can be exploited to promote C3(sp(2))-Si bond functionalization through intramolecular activation. This study introduces versatile platforms for the synthesis of 3-substituted 2-furyl carbinols from renewable feedstock.
BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Gredy Kiala Kinkutu, Catherine Louis, Myriam Roy, Juliette Blanchard, Julie Oble
Summary: In order to develop a continuous flow process for the C3-alkylation of furfural, we optimized the reaction conditions using a pulsed-flow system and then successfully transferred them to a continuous flow reactor. This allowed for the C3-alkylation of furfural to be carried out in a safer and more efficient manner.
BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Yang Liu, Mikael La Roch, Alessia Mori, Alexandre Pradal, Giovanni Poli, Julie Oble
Summary: The article introduces a Pd(II)-catalyzed [3+2] annulation strategy, which replaces α,β-unsaturated-γ-oxy carbonyls with β,γ-unsaturated carbonyl derivatives as bis-electrophiles. The study provides experimental optimization and demonstrates the synthetic versatility in forming diverse heterocyclic structures. This dehydrogenative strategy represents a more economical version than the previous redox-neutral couplings.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Camilla Loro, Marta Papis, Francesca Foschi, Gianluigi Broggini, Giovanni Poli, Julie Oble
Summary: A new straightforward approach to synthesizing 1-aryl-2-aminopropanes has been developed using a simple and accessible substrate. This approach involves cascade reactions with arenes and sulfonamide nucleophiles catalyzed by Cu(OTf)(2), resulting in regioselective formation of 1-aryl-2-aminopropanes. The reaction is expected to proceed through a Friedel-Crafts-type allylation of the arene followed by hydroamination.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Marta Papis, Raffaella Bucci, Alessandro Contini, Maria Luisa Gelmi, Leonardo Lo Presti, Giovanni Poli, Gianluigi Broggini, Camilla Loro
Summary: A phosphine-catalyzed domino assembly of six units of 2-bromomethyl acrylates was developed to synthesize polyalkenyl adducts containing two cyclohexenyl rings. This method involves initial dimerization and subsequent trimerization of the substrate, resulting in the formation of seven carbon-carbon bonds and four stereocenters. The protocol has also been successfully scaled up to gram-scale experiments.
