Article
Chemistry, Multidisciplinary
Yao Xu, Hai-Xiang Gao, Chengkai Pan, Yue Shi, Chi Zhang, Genping Huang, Chao Feng
Summary: By using photoredox catalysis, we have achieved the (3+3) dipolar cycloaddition of nitrones with aryl cyclopropanes. This reaction exhibits excellent regio- and stereoselectivity and can be applied to a variety of aryl cyclopropane substrates.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Illia Lenko, Alexander Mamontov, Carole Alayrac, Remi Legay, Bernhard Witulski
Summary: The research demonstrates the divergent Pd-catalyzed reaction cascades with various 1,3-diynamides, leading to different products depending on the presence or absence of TBAF. Furthermore, deuterium labeling experiments reveal the unique formation mechanism of the products.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Tobias Sandmeier, Erick M. Carreira
Summary: The study introduces the enantio- and chemoselective N-allylation of oximes, yielding cyclic nitrones and enantioenriched aliphatic allylic alcohols through intramolecular kinetic resolution. The method stands out for its ability to utilize E/Z-isomeric oxime mixtures convergently and high functional group tolerance, showcasing its synthetic utility with the formal synthesis of (+)-halichlorine.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Yuki Nishida, Takumi Suzuki, Yuri Takagi, Emi Amma, Ryoya Tajima, Satoru Kuwano, Takayoshi Arai
Summary: The stable hypervalent cyclic dibenzoiodolium salt acts as a strong halogen bonding donor catalyst for [4+2] cycloaddition reactions, rather than an oxidizing agent. This catalyst is effective in promoting both [4+2] cycloaddition reactions of 2-alkenylindoles and Povarov reactions with high yields.
Article
Chemistry, Multidisciplinary
Fei Tian, Wu-Lin Yang, Tao Ni, Jian Zhang, Wei-Ping Deng
Summary: The development of efficient methods for synthesizing chiral polycyclic indoles is crucial for their wide applications in medicines, pesticides, and other functional molecules. The study revealed novel indolyl substituted metal-allyl zwitterionic intermediates that could participate in asymmetric cycloaddition reactions with high selectivities, leading to the synthesis of diverse chiral polycyclic indoles.
SCIENCE CHINA-CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Callum R. Woof, Derek J. Durand, Ruth L. Webster
Summary: An iron(II)-catalyzed polymerization of arylallenes has been reported, generating high molecular weight polymers at room temperature. The polymer structures and chain lengths of various monomers were determined using NMR, DSC, and GPC analysis. Mechanistically, it is proposed that chain growth occurs through a reactive Fe(III) species, rather than the formation of an iron(II) hydride in situ.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Physical
Jessica Rodriguez, David Vesseur, Alexis Tabey, Sonia Mallet-Ladeira, Karinne Miqueu, Didier Bourissou
Summary: A (MeDalphos)AuCI complex has been discovered to efficiently catalyze the cross-coupling reaction of indoles and allyl acetates/alcohols. The reaction tolerates various functional groups and selectively produces branched C3-allylated products. It utilizes the hemilabile character of the P<^>N ligand.
Article
Chemistry, Multidisciplinary
Chang-Sheng Wang, Qiao Sun, Felipe Garcia, Chen Wang, Naohiko Yoshikai
Summary: The study presents a simple and inexpensive catalytic system based on cobalt(II) iodide, 1,3-bis(diphenylphosphino)propane, and Zn for the [2+2+2] cycloaddition of various nitriles and diarylacetylenes to synthesize a broad range of polyarylated pyridines. DFT studies support a reaction pathway involving oxidative coupling of two alkynes, insertion of the nitrile into a cobaltacyclopentadiene, and C-N reductive elimination, leading to the synthesis of tetra- and pentaarylpyridines that can be used as precursors for nitrogen-containing polycyclic aromatic hydrocarbons.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Lin Chen, Wen-Ya Jiao
Summary: Using renewable biomass chitosan as raw material, crosslinked chitosan microsphere (CCM) was prepared and used to fabricate CCM-supported Yb(OTf)(3) (Yb(OTf)(3)@CCM). The Yb(OTf)(3)@CCM acted as a green heterogeneous catalyst for the three-component [3+2] cycloaddition, providing a range of architecturally complex bispiro-fused heterocycles with high yields and diastereoselectivities. The catalyst could be easily recovered and reused multiple times with acceptable catalytic activity remaining.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Alexander Aksenov, Dmitrii A. Aksenov, Nicolai A. Aksenov, Anton A. Skomorokhov, Elena Aleksandrova, Michael Rubin
Summary: This study utilized a highly efficient one-pot procedure to prepare diastereomerically selective 4'H-spiro[indole-3,5'-isoxazoles] by combining conjugate addition of Grignard reagents to (2-nitroalkenyl)indoles with subsequent Bronsted acid-assisted spirocyclization. The use of alkyl Grignard reagents provided easy access to 4'-alkylsubstituted derivatives that are difficult to obtain by other means.
Review
Chemistry, Multidisciplinary
Runjiang Song, Yongtao Xie, Zhichao Jin, Yonggui Robin Chi
Summary: NHC catalysis has shown great potential in accessing atropisomeric molecules, offering unique reaction modes for asymmetric synthesis. The progress in this field includes kinetic resolutions, asymmetric desymmetrizations, and the conversion of central-to-axial chirality, highlighting the promising future applications of NHC-based organic catalysis in preparing challenging atropisomeric compounds.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Applied
Hao Yuan, Dong-Liu Lu, Cui Liang, Dong-Liang Mo
Summary: Various spirooxindole-benzo[d]oxazoles and dihydrobenzofurans were successfully synthesized via transition metal-free [3 + 2] cycloaddition and selective rearrangement. The substituent on the N-vinyl group of the nitrone was found to control the [1,3]- or [3,3]-rearrangement of the cycloadduct due to steric effects. This method demonstrates broad substrate scope, good functional group tolerance, controllable rearrangement, and diverse oxindole scaffolds.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Applied
Rayhane Hammami, Pascale Maldivi, Christian Philouze, Sebastien Carret, Benjamin Darses, Soufiane Touil, Jean-Francois Poisson
Summary: A variety of 4-phosphinylpyrrolidin-3-ones were synthesized via a [3+2] cycloaddition reaction between aryl aldonitrones and phosphinylallenes. The products were obtained as unique 4,5-trans diastereomers in yields ranging from 47% to 80% for 23 examples. Chiral racemic allenes exhibited a moderate 2:1 to 4:1 2,5-diastereoselectivity. Under the reaction conditions, the cycloadducts undergo a rearrangement to selectively afford the corresponding pyrrolidin-3-ones. DFT calculations provided insights into the mechanism involving the homolytic cleavage of the N-O bond of the cycloadduct.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Applied
Sayaji Arjun More, Tzu-Hsuan Chao, Mu-Jeng Cheng, Rai-Shung Liu
Summary: A gold-catalyzed synthesis method for 1,3-dihydrooxazolo[3,4-a]indoles from 1-oxo-3-yn-4-ols and nitrones is described. The research demonstrates that internal alkynes can undergo oxoarylation reaction with nitrones, revealing the underlying chemical mechanism.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Bradley K. Gall, Avery K. Smith, Eric M. Ferreira
Summary: A direct dearomative photocatalyzed (3+2) cycloaddition between indoles and vinyldiazo reagents is achieved using a novel oxidizing Cr-III photocatalyst. This transformation allows the synthesis of various fused indoline compounds, including densely functionalized ring systems, under base-free conditions. Experimental insights support a cycloaddition initiated by nucleophilic attack of the vinyldiazo species at C3 of the indole radical cation.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
