Review
Chemistry, Organic
Pushpinder Singh, Mritunjay
Summary: Dialkyl azodicarboxylates have been widely used in synthetic strategies other than Mitsunobu reactions, serving as oxidants or dehydrogenating reagents in oxidative transformations and different types of bond construction. Recently, they have also been explored in photochemical reactions, showcasing their oxidative abilities and advantageous features.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Kentaro Sakai, Kounosuke Oisaki, Motomu Kanai
Summary: Selective C(sp(3))-H functionalization using photoredox catalysis and hydrogen atom transfer catalysis has attracted increasing attention. We report the use of a Ph2GeCl2 cocatalyst that greatly improves the yield of alpha-C(sp(3))-H alkylation of primary amines catalyzed by a PC-HAT hybrid system. The alpha-position of the amino group selectively reacts, even when weaker C-H bonds exist in the substrates. This finding may aid in the design of novel site-selective hybrid catalysis.
Article
Chemistry, Organic
Naya A. A. Stini, Efthymios T. T. Poursaitidis, Nikolaos F. F. Nikitas, Michail Kartsinis, Nikoleta Spiliopoulou, Phoebe Ananida-Dasenaki, Christoforos G. G. Kokotos
Summary: The hydroacylation of dialkyl azodicarboxylates has attracted significant attention recently due to the importance of acyl hydrazides in organic chemistry. In this study, an inexpensive and environmentally friendly photochemical approach using light irradiation (390 nm) and water as the solvent was developed to accelerate the reaction between dialkyl azodicarboxylates and aldehydes. Various aromatic and aliphatic aldehydes were efficiently converted into their corresponding acyl hydrazides in short reaction times (15-210 min) and the reaction mechanism was investigated. The application of this reaction in the synthesis of Vorinostat and Moclobemide was also demonstrated.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Organic
Daniel P. Schwinger, Thomas Pickl, Thorsten Bach
Summary: Cyclohept-1-ene-1-carbaldehyde undergoes photoinduced E & RARR; Z isomerization at & lambda; =350 nm. The ring strain facilitates various reactions, including Diels-Alder cycloadditions, [3 + 2] cycloadditions, and enereactions. The products obtained are trans-fusedat the cycloheptane core and yield up to 82%. Single crystal X-ray analyses confirm the structure and relative configuration. In the presence of BF3 and 2,3-dimethylbuta-1,3-diene, cyclohept-1-ene-1-carbaldehyde undergoes a stereoselective rearrangement to form a tricyclic ketone (87%).
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Yue Xia, Nicholas W. Wade, Philip N. Palermo, Yidong Wang, Yi-Ming Wang
Summary: This study presents a novel method using iron catalysis to convert simple monosubstituted allenes into 1-tetrahydroisoquinolinyl 1,1-disubstituted allenes, marking a significant advance in chemical synthesis. The optimized protocol shows a wide scope and mild, functional group tolerant conditions.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Vijayanath Elakkat, Eskedar Tessema, Chia-Her Lin, Xiaoping Wang, Huan-Cheng Chang, You-Ning Zheng, Yu-Cheng Huang, Zhong-Yun Gurumallappa, Zhong-Yun Zhang, Ka Long A. Chan, Hening A. S. Rahayu, Joseph S. Francisco, Norman Lu
Summary: To understand the effect of non-covalent weak interactions on molecules, we investigated different types of weak interactions in fluorinated chiral zinc complexes, including improper H-bonding, tetrel bonds, and halogen bonds. High resolution neutron diffraction studies revealed elongation and shortening of the methylene carbon-hydrogen bond due to tetrel bonds and improper H-bond interactions, respectively. We demonstrated how multiple weak interactions can cumulatively affect the C-H bond and offset its elongation through formation of an improper H-bond. Non-covalent interaction and electrostatic potential analysis investigations confirmed the nature of these interactions using density functional theory (DFT) and related calculations.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Environmental Sciences
Roberto Camposeco, Omar Miguel, Ana E. Torres, Daniela E. Armas, Rodolfo Zanella
Summary: Ruthenium catalysts supported on TiO2 were synthesized and tested for the catalytic oxidation of C3H8. The catalytic activity and physicochemical properties of the catalysts were investigated, and the effects of ruthenium loading, particle size, and support interaction on the catalytic performance were studied. The results showed that the 2 wt. % Ru/TiO2 catalyst exhibited the highest catalytic reactivity, and the stability and reusability of the catalyst were also demonstrated.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Chemistry, Physical
Zhiyao Zheng, Luca Deiana, Daniels Posevins, Abdolrahim A. Rafi, Kaiheng Zhang, Magnus J. Johansson, Cheuk-Wai Tai, Armando Cordova, Jan-E Backvall
Summary: In this study, an efficient nanocopper-catalyzed Alder-ene reaction of allenynamides is described. Copper nanoparticles were immobilized on amino-functionalized micro-crystalline cellulose. The reaction exhibited solvent-controlled chemoselectivity, leading to the synthesis of pyrrolines and pyrroles. The heterogeneous copper catalyst showed high efficiency and recyclability in the Alder-ene reaction, making it a highly attractive catalytic system from an economic and environmental perspective.
Article
Green & Sustainable Science & Technology
Zengyong Li, Di Li, Jiaojiao Ma, Ren Zou, Xuehui Li, Chuanfu Liu, Xinwen Peng
Summary: The study successfully synthesized a high-performance Ni-NCNT catalyst for selectively converting monosaccharides into high value-added sugar acids. Key steps in the oxidation of xylose include dissociation of the formyl C-H bond and formation of adsorbed xylonic acid.
Article
Chemistry, Multidisciplinary
Edina Reizer, Bela Fiser
Summary: The reaction initiation points of the 16 priority polycyclic aromatic hydrocarbons (PAHs) have been determined by calculating the different C-H bond dissociation enthalpy (BDE) values. Six density functional theory methods and four basis sets were applied, and the most feasible combination was selected. Most of the hydrogen atoms are in zig-zag positions, and the BDE and bond length values for the PAHs range between certain values. The initiation points are mostly represented by armchair and peak hydrogens.
ARABIAN JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Organic
David F. Fernandez, Maria Gonzalez-Esguevillas, Sebastian Keess, Felix Schafer, Jens Mohr, Andre Shavnya, Thomas Knauber, David C. Blakemore, David W. C. MacMillan
Summary: We present a general approach to synthesis of diversified libraries featuring aliphatic core rings via photoredox catalysis under mild conditions.
Article
Chemistry, Multidisciplinary
Anirudra Paul, Jae Hyun Kim, Scott D. Daniel, Daniel Seidel
Summary: Despite efforts by practitioners, direct alpha-C-H bond functionalization of unprotected alicyclic amines is rare. A new method utilizing N-lithiated alicyclic amines has been developed, providing a convenient approach to achieve functionalization reactions under mild conditions. This method offers a new pathway for the synthesis of beta-amino ketones with regioselective alpha'-alkylation, and potential for one-pot synthesis of polycyclic dihydroquinolones.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Kseniya A. Alekseeva, Maryana A. Nadirova, Vladimir P. Zaytsev, Evgeniya V. Nikitina, Mikhail S. Grigoriev, Anton P. Novikov, Irina A. Kolesnik, Bernhard Mayer, Thomas J. J. Mueller, Fedor I. Zubkov
Summary: Diversely substituted, partially saturated benzo-[f]-isoindole-4-carboxylic acids were synthesized through a new three-component reaction. The reaction showed high regio- and stereoselectivity, resulting in the formation of a chiral center and a diastereoisomer.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Yasuhiro Yamashita, Io Sato, Ryota Fukuyama, Shu Kobayashi
Summary: Catalytic imino-ene-type allylation reactions of unactivated allyl compounds were achieved using a catalytic amount of a strongly basic mixed system. The reactions proceeded smoothly at low temperature, and notably, the gaseous alkene propylene could be used in this system.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Organic
De Wang, Zefeng Song, Jianyu Zhang, Tao Xu
Summary: A novel remote delta methylene C(sp(3))-H functionalization was discovered, catalyzed by an organophosphine through alkyne isomerization/conjugate addition cascade without the need for a classical electron-withdrawing group. The process, under only 10 mol% of PMe2Ph with a catalytic proton shuttle, successfully produced a large group of functionalized products with good diastereoselectivity. Mechanistic studies and fluorescence properties of the conjugated polyene products were investigated in detail.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Organic
Deping Kong, Hongli Wu, Jiaao Ge, Zhen Shen, Genping Huang
Summary: Density functional theory calculations were used to investigate the cobalt-catalyzed intermolecular hydro-arylation/cyclization reaction. The computations revealed that the reaction proceeds through an oxidative cyclization of 1,6-enynes, followed by metal-assisted sigma-bond metathesis/reductive elimination, leading to the final hydroarylation/cyclization product. The steric repulsion and pi···pi interaction were found to be crucial in determining the observed enantioselectivity.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Chenchen Zou, Hongli Wu, Yuqi Ji, Penglin Zhang, Huanhuan Cui, Genping Huang, Chun Zhang
Summary: The palladium-catalyzed borylative cyclization via C-H activation has been developed for the construction of indole-fused dihydro-pyrrole motif with a boric ester group. The study further demonstrates the potential applications of the products and the control of enantioselectivity by using chiral ligand. The borylative mechanism has been proposed based on DFT calculations.
CHINESE JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Organic
Juanjuan Wu, Hongli Wu, Xinyu Liu, Yuekun Zhang, Genping Huang, Chun Zhang
Summary: A nickel-catalyzed reductive cross-coupling reaction has been developed for the synthesis of chiral α-CF3 ketones with high enantioselectivity and good functional group tolerance. The study of late-stage transformation demonstrated its applicability in preparing bioactive compounds. Control experiments further indicated the importance of the α-trifluoromethyl group in this reaction.
Article
Chemistry, Physical
Jiapan Niu, Hongli Wu, Changhao Niu, Genping Huang, Chun Zhang
Summary: A practical palladium and amino acid co-catalyzed hydroarylation of unbiased alkenes has been developed, which can construct isolated chiral Csp(2)-Csp(3) bonds with good regio- and enantioselectivity. The potential synthetic utility of a representative product was wellillustrated by further transformations. Furthermore, the mechanism of this reaction was intensively studied through control experiments and DFT calculations.
Article
Chemistry, Multidisciplinary
Jiang-Fei Li, Deng Pan, Hao-Rui Wang, Tao Zhang, Yi Li, Genping Huang, Mengchun Ye
Summary: A chiral phosphine oxide-ligated Ni-Al bimetallic catalyst was successfully utilized for an enantioselective C2-H alkylation of pyridines, showing compatibility with a wide range of pyridine substrates and providing high yields and enantioselectivities.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Siyuan Su, Tongtong Wu, Yuanzhi Xia, Donald J. Wink, Daesung Lee
Summary: The cycloisomerization of alkyne-tethered N-benzoyloxycarbamates to 2-(3H)oxazolones is reported. Two catalytic systems are developed for intramolecular 5-exo-alkyne carboxyamidation and alkene isomerization. PtCl2/CO and FeCl3 are effective catalysts, but FeCl3 requires a cocatalyst for alkene isomerization. A two-step one-pot protocol is established for a broader reaction scope, involving FeCl3-catalyzed carboxyamidation and base-induced alkene isomerization. Crossover experiments suggest the involvement of acylnitrenoid intermediates in these reactions.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Shuqi Kong, Mengyao Zhang, Shiyu Wang, Hongli Wu, Hongyan Zou, Genping Huang
Summary: Density functional theory calculations were used to study the palladium-catalyzed remote diborylative cyclization of dienes. The computations revealed a Pd(II)/Pd(IV) catalytic cycle and the involvement of a high-valent Pd(IV) species in the sigma-bond metathesis between the alkylpalladium intermediate and B(2)pin(2) via B-B oxidative addition/C-B reductive elimination. The diastereoselectivity was found to be determined by the migratory insertion into the Pd-C bond, influenced by torsional strain, steric repulsion, and C-H-O hydrogen bonding.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
Article
Chemistry, Organic
Qiao Li, Yanshu Luo, Jianhui Chen, Yuanzhi Xia
Summary: A catalyst- and metal-free hydrogenation of azobenzenes to hydrazobenzenes in the presence of thioacetic acid was achieved under visible light irradiation. The transformation was carried out under mild conditions in an air atmosphere at ambient temperature, generating a variety of hydrazobenzenes with yields up to 99%. The current process is compatible with a variety of substituents and is highly chemoselective for azo reduction when other unsaturated functionalities (carbonyl, alkenyl, alkynyl, etc.) are contained. Preliminary mechanistic study indicated that the transformation could be a radical process.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Peiyuan Wang, Hongli Wu, Xue-Peng Zhang, Genping Huang, Robert H. Crabtree, Xingwei Li
Summary: In this study, atroposelective access to C-N axially chiral isoquinolones was achieved via rhodium-catalyzed C-H activation of N-alkoxy benzamides and annulation with imidoyl sulfoxonium ylides. The coupling system showed excellent functional group tolerance and afforded enantiomeric products with high enantioselectivity by using different reaction conditions for a representative sulfoxonium ylide reagent. Experimental and computational studies identified a pathway involving C-H alkylation and enantio-determining formal nucleophilic substitution-C-N cyclization, mediated by the rhodium catalyst through sigma-bond metathesis as the asymmetric induction mechanism. Solvent-dependent enantiodivergence was found to originate from different levels of sigma-bond metathesis mediated by neutral versus cationic rhodium species.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Huiting Wen, Yifei Chen, Lanxuan Shi, Jianhui Chen, Yanshu Luo, Yuanzhi Xia
Summary: An asymmetric hydrosilylation of alpha-oxygenated ketones was developed using Co(OAc)2 as the catalyst in combination with a chiral PAO ligand. This method provides a mild, efficient, and enantioselective access to a variety of synthetically useful 1,2-diol derivatives. The synthetic utility of this protocol was demonstrated by efficient conversion of the optically enriched products into chiral alpha-hydroxy acid, 1,3-dioxolan-2-one, ethylene oxide, and 1,2,3-1H-triazole.
Article
Chemistry, Organic
Risong Wang, Yifei Chen, Binjie Fei, Jiahao Hu, Jianhui Chen, Yanshu Luo, Yuanzhi Xia
Summary: Condition-dependent transformations between hydroximic acids and thioacetic acid were achieved, where NH4HCO3 and ethanol resulted in N-O bond cleavage to afford primary amides, and NEt3 and H2O led to O-acylation. The transformations could be scaled up to the gram level smoothly. Preliminary mechanistic studies suggested a cascade process of acylation/reduction for N-O bond cleavage.
Article
Chemistry, Physical
Bing Li, Yanshu Luo, Min Liu, Yuanzhi Xia, Changkun Li
Summary: The abnormal Claisen rearrangement of phenyl allyl ether with the gamma-alkyl group is well-known, but its asymmetric version has not been reported before. In this study, a highly regio- and enantioselective allylic alkylation of 4-hydroxycoumarin was developed as a formal abnormal Claisen rearrangement. Chiral 4-hydroxycoumarins with 3-allyl groups were synthesized with high yield and enantiomeric excess using rhodium catalyst and chiral bioxazolinephosphine ligand. Experimental and theoretical investigations revealed that the stereospecific rearrangement occurs through the reversible formation of a kinetically favored cis-disubstituted spirocyclopropane intermediate.
Article
Multidisciplinary Sciences
Yishou Wang, Xiaohan Zhu, Deng Pan, Jierui Jing, Fen Wang, Ruijie Mi, Genping Huang, Xingwei Li
Summary: Here, the authors report the construction of diverse classes of diaxially chiral biaryls containing N-N and C-N/C-C diaxes in excellent stereo- and diastereoselectivity. The N-N chiral axis in the products allows for solvent-driven diastereodivergence, as demonstrated in the coupling of benzamides and sterically hindered alkynes. The mechanism of diastereodivergence is elucidated through computational studies, revealing the role of hexafluoroisopropanol (HFIP) as a solvent and ligand.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Xiaohan Zhu, Hongli Wu, Yishou Wang, Genping Huang, Fen Wang, Xingwei Li
Summary: In this study, we report the rhodium-catalyzed enantioselective [4 + 2] oxidative annulation of internal alkynes with benzamides bearing two classes of N-N directing groups. The coupling occurs under mild conditions via NH and CH annulation through the dynamic kinetic transformation of the directing group and shows high enantioselectivity with good functional tolerance.
Article
Chemistry, Organic
Xinyi Song, Hongli Wu, Jinjin Yang, Wentao Zhao, Genping Huang
Summary: Density functional theory calculations were used to investigate the mechanism of copper-catalyzed borocarbonylation of imines with B(2)pin(2) and alkyl iodides. The calculations showed that the reaction starts with the selective migratory insertion of the C-N double bond into the Cu-B bond to form the key alpha-boryl amido-copper complex, which can undergo a stepwise rearrangement to give alpha-amino alkyl-copper species. The C-I bond cleavage of alkyl iodide through halogen-atom abstraction, radical association, and reductive elimination leads to the formation of alpha-boryl amide and alpha-amino ketone products. The regioselectivity of the reaction is determined by the competition between the 1,2-rearrangement and C-I bond cleavage from the alpha-boryl amido-copper complex, which is in good agreement with experimental observations.
ORGANIC CHEMISTRY FRONTIERS
(2023)
