Article
Chemistry, Organic
Cidan Lv, Xiangxiang Meng, Min Wang, Yan Zhang, Changwei Hu, Chan Kyung Kim, Zhishan Su
Summary: The mechanism and stereoselectivity of an asymmetric cyclopropanation reaction between 3-alkenyl-oxindole and sulfoxonium ylide catalyzed by a chiral N,N'-dioxide-Mg(II) complex were explored. The presence of N-protecting groups in the isatin enhanced the reactivity of the reactants, while steric effects of substituents in the chiral ligand played a crucial role in the selectivity of the reaction.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Rachel J. Baker, Justin Ching, Teh Ren Hou, Ivan Franzoni, Mark Lautens
Summary: The dearomatization of 2-naphthols is a simple method for constructing complex 3D structures from simple planar starting materials using rhodium and acid catalysis under mild conditions. The vinyl cyclopropane molecules formed in this reaction exhibit high chemoselectivity and scalability, and can be further functionalized at different sites. Both computational and experimental evidence were used to understand the reaction mechanism.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Matthias Peeters, Jonathan Decaens, Alois Fuerstner
Summary: Chiral [BiRh]-paddlewheel complexes empowered by London dispersion enable the generation of (trifluoromethyl)furfurylidene metal complexes from a bench-stable triftosylhydrazone precursor. These complexes undergo asymmetric [2+1] cycloadditions, providing optically active trifluoromethylated cyclopropane or -cyclopropene derivatives, which are important building blocks for medicinal chemistry and difficult to obtain in optically active form.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Review
Chemistry, Multidisciplinary
Santosh Kumar Sahu, Pradyota Kumar Behera, Prabhupada Choudhury, Madhusudan Sethi, Satyaban Jena, Laxmidhar Rout
Summary: This study summarizes the stereochemical outcomes of [3+2] cycloaddition using rhodium carbene-mediated diazo decomposition for highly diastereoselective poly oxacarbocycles formation. Further exploration with other transition metals and ylides is needed for synthesis of bridged polyheterocycles with potential drug candidate structures similar to known compounds like anthecularin, artemisinin, englerin and intracarene. This review presents a future outlook for organic chemists to explore the synthesis of bridged polyheterocarbocycles.
NEW JOURNAL OF CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Junyou Zhang, Weici Xu, Ming-Hua Xu
Summary: A simple and broad-scope rhodium(I)/chiral diene catalytic system was developed for challenging asymmetric intramolecular cyclopropanation of various tri-substituted allylic diazoacetates. The low coordination state Rh-I-complex exhibited high tolerance to substitution of the allyl double bond, enabling the efficient construction of penta-substituted, fused-ring cyclopropanes with three stereogenic centers in a highly enantioselective manner. DFT calculations suggested that pi-pi stacking interactions between the aromatic rings of the chiral diene ligand and diazo substrate played a key role in controlling the reaction enantioselectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Jun Cao, Stephane P. Vincent
Summary: A general methodology for preparing phosphonylated 1-spirocyclopropyl analogues of glycosyl-1phosphates is reported. The reaction showed stereospecificity, with cis/trans selectivity depending on the E/Z configuration of the starting exo-glycal. Four different spirocyclopropyl ribose-1-phosphonate isomers could be prepared in a controlled manner.
Article
Chemistry, Physical
Jack C. Sharland, David Dunstan, Dyuti Majumdar, Jinhai Gao, Kian Tan, Hasnain A. Malik, Huw M. L. Davies
Summary: In the presence of HFIP, nucleophilic and reactive reagents are prevented from interacting with a rhodium carbene, allowing for efficient asymmetric cyclopropanation with high yield and stereoselectivity on a variety of compounds. A high-throughput screen was conducted to expand the scope of the reaction and develop complementary catalytic systems, leading to the enantioselective functionalization of complex molecules including API and natural products.
Article
Chemistry, Physical
Ouidad Lahtigui, Dan Forster, Coralie Duchemin, Nicolai Cramer
Summary: In this study, a flexible two-step protocol for the efficient and selective synthesis of rigid saturated nitrogen-containing scaffolds was disclosed. The method involves alkenyl C-H functionalization and cyclization reactions mediated by C*Rh-III and Cp*Ir-III catalysts, respectively, leading to the synthesis of diverse substituted 3-azabicyclo[3.1.0]hexanes.
Article
Chemistry, Organic
Bo-Wen Pan, Yang Shi, Su-Zhen Dong, Jun-Xiong He, Bo-Shuai Mu, Wen-Biao Wu, Ying Zhou, Feng Zhou, Jian Zhou
Summary: This study presents a highly stereoselective catalytic reaction for the construction of spirocycles. The synthesized compounds exhibit potent antiproliferative activity and have the potential for the treatment of various diseases.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Inorganic & Nuclear
Anna M. Szczepkowska, Mateusz Janeta, Milosz Siczek, Wlodzimierz Tylus, Anna M. Trzeciak, Wojciech Bury
Summary: Two model porphyrin metal-organic frameworks were utilized for the incorporation of Rh(I) species through post-synthetic metallation, resulting in the synthesis and structural characterization of new rhodium MOFs (Rh/MOFs), Rh/PCN-222 and Rh/NU-1102. These Rh/MOFs were demonstrated to be active heterogeneous catalysts for the hydrogenation of unsaturated hydrocarbons at mild reaction conditions, with an activation step required during the initial run of the catalytic process. In situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) was utilized to monitor the activation pathway of the catalyst under a H-2 atmosphere.
DALTON TRANSACTIONS
(2021)
Article
Chemistry, Inorganic & Nuclear
Croix J. Laconsay, Anna Pla-Quintana, Dean J. Tantillo
Summary: Density functional theory calculations were used to investigate the effects of axial ligation by solvent molecules on reactivity and selectivity of dirhodium tetracarboxylates with diazo compounds in C-H insertion reactions. The results suggest that axial ligation significantly influences the barriers for N-2 extrusion and C-H insertion, with a greater impact on the former.
Article
Chemistry, Inorganic & Nuclear
Xiangjun Kong, Yunjun Shen, Hedong Bian, Yuzhen Zhang
Summary: We describe three Pt(ii) diimine complexes with phenylpyridine ancillary ligands and anionic closo-monocarborane clusters [CB11H12](-). These three neutral complexes exhibit intense phosphorescence in the solid state, and complex 1 is used to detect acetonitrile vapor on a quartz plate.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Multidisciplinary
Dong Zhu, Tongxiang Cao, Kai Chen, Shifa Zhu
Summary: The chiral dirhodium(ii) tetracarboxylate-catalyzed enantioselective intramolecular Buchner reaction of donor/donor-carbenes was reported, leading to the synthesis of valuable chiral polycyclic products. Both aryloxy enynones and diazo compounds served as efficient carbene precursors. Excellent yields and outstanding enantioselectivities were achieved. The racemization of one product under specific conditions was explained through a proposed diradical-involved mechanism. Furthermore, asymmetric aromatic substitution with biaryl enynones as carbene precursors allowed for the synthesis of furyl substituted chiral fluorene derivatives.
Article
Chemistry, Multidisciplinary
Lorenz E. Loeffler, Michael Buchsteiner, Lee R. Collins, Fabio P. Calo, Santanu Singha, Alois Fuerstner
Summary: A more convenient and higher-yielding preparation method for [Rh-2(MEPY)(4)] catalyst is presented in this study, along with an improved preparation method for [BiRh(OTfa)(4)], making these compounds more readily available. The reactivity difference between [BiRh(MEPY)(4)] and [Rh-2(MEPY)(4)] in asymmetric synthesis is revealed, with DFT calculations uncovering the reasons for this inertness.
HELVETICA CHIMICA ACTA
(2021)
Article
Chemistry, Organic
Cristian Zavala, Ampofo Darko
Summary: Hammett correlation experiments were conducted to investigate the influence of dirhodium(II,II) paddlewheel complexes with tethered, axially coordinated ligands (TACLs) on the selectivity of rhodium carbenoids in cyclopropanation reactions. The results indicate that dirhodium(II,II) paddlewheel complexes with TACLs are less affected by changes in electronics and decrease selectivity in cyclopropanation reactions with acceptor-substituted rhodium carbenoids. Additionally, Hammett plots using aryl diazoacetates showed a nonlinear downward curvature, suggesting a change in the rate-limiting step of the carbene transfer reaction.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Geeta Devi Yadav, Pooja Chaudhary, Balaram Pani, Surendra Singh
Summary: Chiral transition metal complexes with privileged ligands are efficient catalysts for various asymmetric organic transformations. Transition metal complexes of C1-symmetric pyrrolidine-based ligands have been widely used in asymmetric organic reactions. However, a comprehensive review article on the transition metal complexes of chiral C1-symmetric pyrrolidine-based ligands derived from (L)-proline has not been published.
TETRAHEDRON LETTERS
(2024)
