Article
Multidisciplinary Sciences
Sangbin Park, Gyumin Kang, Chansu Kim, Dongwook Kim, Sunkyu Han
Summary: Securinega alkaloids have been a subject of interest in synthetic chemistry for a long time. This study presents a synthetic solution to accessing high-oxidation state securinega alkaloids by completing the total synthesis of various C4-oxygenated securinine-type alkaloids. The discoveries in this study offer a fundamental synthetic solution to all known securinine-type natural products and could be useful for systematic biological studies.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Xin Chang, Xiang Cheng, Chun-Jiang Wang
Summary: This article introduces an efficient method for synthesizing pharmaceutical compounds with deuterium labels, which addresses the challenge of building deuterium-containing stereogenic centers in organic synthesis. By combining H/D exchange and 1,3-dipolar cycloaddition in a catalytic asymmetric strategy, bioactive alpha-deuterated pyrrolidine derivatives were constructed with high yields and excellent stereoselectivities.
Article
Chemistry, Organic
Pei Dong, Long Chen, Zhendong Yang, Shunxi Dong, Xiaoming Feng
Summary: In this study, an asymmetric catalytic tandem cycloisomerization/[3 + 2] cycloaddition was achieved by a combined system of Au(i) and a chiral N,N'-dioxide-Dy(iii) complex, resulting in various enantioenriched 3H-spiroisobenzofuran-1,3'-pyrrolidine derivatives with moderate to good yields and high diastereo- and enantioselectivities. Possible working modes were proposed to understand the origin of chiral control based on control experiments and the absolute configuration of the product.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Physical
Connor Kabes, Reagan Lucas, Jack Gunn, John Gladysz
Summary: The lipophilic diastereomeric cobalt complexes catalyze enantioselective C-H bond addition reactions with aliphatic tertiary amines. Incorporating different bases into counter anions can lead to highly enantioselective bifunctional catalysts, where salts of nicotinates and related compounds have been found effective. The 6-aminonicotinate salt gives the best results among the tested bases.
Article
Chemistry, Physical
Yinwu Li, Huayu Liang, Yubang Liu, Jiaxing Lin, Zhuofeng Ke
Summary: In this study, the catalytic properties of silicon-based and silane-based active species in Si-Ni complex-catalyzed selective hydrogenation were revealed through density functional theory calculations. The roles of silicon as silyl and silane during the catalysis were well explained, providing valuable insights into the mechanism and role of silicon in Si-Ni-catalyzed hydrogenation.
Article
Chemistry, Organic
Rudolfs Belaunieks, Mikus Purins, Viktors Kumpins, Maris Turks
Summary: Protonation of propargylsilanes in liquid SO2 leads to 1,2-silyl group shift and formation of 2-silylated dienes. Subsequent cheletropic SO2 addition results in the formation of 3-silylated 3-sulfolenes, which can be further converted into various types of silanes through reductive desulfitation. Liquid SO2 serves as a polar and Lewis acidic reaction medium, allowing the use of relatively weak Bronsted acid catalysts.
CHEMISTRY OF HETEROCYCLIC COMPOUNDS
(2021)
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)
Article
Chemistry, Organic
Marina Briand, Linh D. Thai, Flavien Bourdreux, Nicolas Vanthuyne, Xavier Moreau, Emmanuel Magnier, Elsa Anselmi, Guillaume Dagousset
Summary: Site-selective trifluoromethylation of silyl dienol ethers derived from alpha,ss-unsaturated aldehydes, ketones, and amides was achieved for the first time in the remote gamma position. An unprecedented enantioselective C(sp(3))-H perfluoroalkylation process is disclosed.
Article
Chemistry, Physical
Pan Gao, Liping Cui, Guodong Zhang, Feng Chen
Summary: A catalytic defluorosilylation method is developed, providing concise and modular synthetic routes for gem-difluoroallylsilanes. Trifluoromethylalkenes and silacarboxylic acids are used as easy-to-prepare and stable silyl radical precursors. This method utilizes photoredox catalysis and features a unique decarboxylation followed by defluorosilylation without extra hydrogen atom transfer catalysis, offering mild reaction conditions and a broad substrate scope applicable to diverse electron-rich and electron-poor groups.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Fu-Li Wang, Chang-Jiang Yang, Ji-Ren Liu, Ning-Yuan Yang, Xiao-Yang Dong, Ruo-Qi Jiang, Xiao-Yong Chang, Zhong-Liang Li, Guo-Xiong Xu, Dai-Lei Yuan, Yu-Shuai Zhang, Qiang-Shuai Gu, Xin Hong, Xin-Yuan Liu
Summary: In contrast to the well-established enantioconvergent radical C(sp(3))-C cross-coupling, the coupling of tertiary electrophiles to forge all-carbon quaternary stereocentres remains unexplored. Here, we demonstrate a general copper-catalysed enantioconvergent C(sp(3))-C(sp) cross-coupling using rational design of chiral ligands. This protocol provides a practical platform for the construction of chiral carbon building blocks of interest in organic synthesis.
Article
Chemistry, Organic
Qinhui Wan, Chen-Yin Huang, Zhong-Wei Hou, Huajiang Jiang, Lei Wang
Summary: An organophotoelectrochemical method has been developed for silylation cyclization of CF3-substituted N-arylacrylamides with organosilanes. This method utilizes 9,10-phenanthrenequinone (PQ) as a catalyst and a hydrogen atom transfer (HAT) reagent, and organosilanes as silyl radical precursors, eliminating the need for oxidants or metal reagents. A series of silylated 3-CF3-2-oxindoles are synthesized with satisfactory yields under simple and mild conditions.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Review
Chemistry, Multidisciplinary
William P. Thomas, Sergey Pronin
Summary: Paxilline-type indoloterpenoids, a large family of secondary metabolites, exhibit unique molecular architectures and a diverse set of biological activities, including neurological and insecticidal activities, modulation of lipid balance, and inhibition of mitosis. Organic chemists have been fascinated by the uniting polycyclic motif and the diversity of individual structural features of paxilline indoloterpenoids for the past four decades, leading to the development of numerous syntheses. The increasing diversity of structural motifs made accessible by application of this chemistry has led to the exploration of new synthetic methods and artificial assembly of terpenoid natural products from different families.
ACCOUNTS OF CHEMICAL RESEARCH
(2021)
Review
Chemistry, Multidisciplinary
Mo Wang, Zhenfeng Zhang, Wanbin Zhang
Summary: This article introduces the development of chiral bicyclic imidazole catalysts by our research group, including their design, synthesis, and application. By using different skeletons and substituents, a series of highly active and selective catalysts were successfully prepared and applied in asymmetric synthesis reactions. This research provides important insights and guidance for exploring new organocatalysts and related reactions.
ACCOUNTS OF CHEMICAL RESEARCH
(2022)
Article
Chemistry, Multidisciplinary
Xin He, Pengchen Ma, Yuhai Tang, Jing Li, Shenyu Shen, Martin J. Lear, K. N. Houk, Silong Xu
Summary: We report a phosphine-catalyzed (3 + 2) annulation of cyclopropenones with various electrophilic pi systems, yielding products including butenolides, butyrolactams, maleimides, and iminomaleimides in high yields with a wide range of substrates. An alpha-ketenyl phosphorous ylide is identified as the key intermediate, which undergoes preferential catalytic cyclization with aldehydes. This phosphine-catalyzed activation of cyclopropenones provides a versatile C-3 synthon for formal cycloadditon reactions.
Article
Chemistry, Organic
Raviramanujayya Tammisetti, Prakash D. Chaudhari, Bor-Cherng Hong, Su-Ying Chien
Summary: A series of iridoids, including iridomyrmecin A, B, C ', D ', (-)-isoiridomyrmecin, (+)-7-epi-boschnialactone, and the inside-yohimbine analogues, have been synthesized from naturally occurring (-)-citronellal via metathesis, organocatalysis, reduction, lactonization, alkylation, Pictet-Spengler reaction, and lactamization. The use of DBU as an additive in the organocatalytic intramolecular Michael reaction showed better stereoselectivity compared to acetic acid as an additive. The structures of three products were determined through single-crystal X-ray crystallographic analyses.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Mrittika Roy, Jeffrey H. Walton, James C. Fettinger, Alan L. Balch
Summary: This study reports a method for the direct synthesis of diamine radical cations in crystalline form through the oxidation of triphenylamine. The results demonstrate that two different products can be obtained depending on the oxidizing agent used.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Organic
Anna Lo, David A. Gutierrez, Garrett Toth-Williams, James C. Fettinger, Jared T. Shaw
Summary: Lewis acid mediated allylations of beta-alkoxy N-tosyl imines using allyltrimethylsilane led to the formation of anti-selective 3-alkoxy homoallylic N-tosyl amines. Two methods of Cu(OTf)(2)-mediated allylations were reported, showing that diastereoselectivity can be achieved through the 1,3 acyclic stereocontrol of beta-chiral aldimines. The observed selectivity trends and computational evidence suggest that selectivity arises through the formation of a six-membered ring chelate.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
David A. Gutierrez, James Fettinger, K. N. Houk, Kaori Ando, Jared T. Shaw
Summary: This study describes the Lewis-acid-promoted addition of prochiral E- and Z-allyl nucleophiles to chiral alpha-alkoxy N-tosyl imines with stereochemical control, resulting in the synthesis of two isomers of clausenamide.
Article
Chemistry, Multidisciplinary
Sarah N. Dishman, Croix J. Laconsay, James C. Fettinger, Dean J. Tantillo, Jared T. Shaw
Summary: Intramolecular C-H insertions with donor/donor dirhodium carbenes provide a concise and highly stereoselective method to set two contiguous stereocenters in a single step. The study demonstrates that donor/donor carbenes undergo uniquely stereoselective reactions that originate from a stepwise reaction mechanism, in contrast to the analogous concerted reactions of carbenes with one or more electron-withdrawing groups attached.
Article
Chemistry, Organic
Benjamin D. Bergstrom, Garrett Toth-Williams, Anna Lo, Jeffrey W. Toman, James. C. Fettinger, Jared T. Shaw
Summary: Polysubstituted allenes are valuable synthetic intermediates that offer structural complexity, modularity, and chirality for further transformations. In this study, a novel method for synthesizing tetrasubstituted allenes with geminal acyl/alkoxy substitution is reported. These unique push-pull allenes demonstrate bench-stability and interesting reactivity in various applications.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Lilia M. Baldauf, James C. Fettinger, Marilyn M. Olmstead, Kamran B. Ghiassi, Alan L. Balch
Summary: Two new cocrystals, named 1 and 2, were discovered with a clamshell arrangement of two porphyrins surrounding a central C70 molecule. Cocrystal 1 has a unique double-clamshell arrangement, while cocrystal 2 has a simple clamshell arrangement.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Chemistry, Inorganic & Nuclear
Rongqing Shang, Allan He, Elizabeth L. Kunz Wille, Na Hyun Jo, James C. Fettinger, Paul C. Canfield, Susan M. Kauzlarich
Summary: The solid solutions of Yb14ZnSb11 with different RE3+ elements were prepared to investigate the intermediate valency of Yb in Yb14ZnSb11. The substitution of Yb with RE3+ elements can impact the valency of Yb ions. Large crystals were grown using Sn-flux, the structure and magnetic susceptibility were studied. The results showed that all compounds crystallize in the Ca14AlSb11 structure type and the RE3+ ions exhibit a size-dependent preference for substitution at the Yb site.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Qihao Zhu, James C. Fettinger, Petra Vasko, Philip P. Power
Summary: A series of tin hydride transition metal complexes were obtained and their structures and reactivity were characterized and studied computationally.
Article
Chemistry, Inorganic & Nuclear
Connor P. McLoughlin, James C. Fettinger, Philip P. Power
Summary: Six new transition-metal aryloxides were synthesized and characterized to compare the steric and dispersive characteristics of their substituents. The results show that the -C6H2-2,4,6-Cy-3 substituent has higher dispersive energy donor properties and influences the thermal stability. Complexes 1 and 2 exhibit high thermal stability and short-contact H···H interactions, while complexes 5 and 6 have a lower association number due to the lower dispersion energy donor properties of the -OC6H3-2,6-Pr-i (2) ligand.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Alice C. Phung, James C. Fettinger, Philip P. Power
Summary: A series of ferriostannylenes with different iron and/or tin substituents were synthesized and their structures and spectroscopic properties were investigated. The results showed that the substituents have significant effects on the structure and properties of the compounds.
JOURNAL OF ORGANOMETALLIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Leo W. T. Parsons, James C. C. Fettinger, Louise A. A. Berben
Summary: This study explores N-alkylation and N-metallation of pyridine to understand how metal-ligand complexes can mimic NAD(+) redox chemistry. The syntheses of substituted dipyrazolylpyridine (pz(2)P) compounds (pz(2)P)Me+ (1(+)) and (pz(2)P)GaCl2+ (2(+)) are reported and compared with previous transition element pz(2)P complexes. Cyclic voltammetry measurements show that cationic 1(+) and 2(+) exhibit irreversible reduction events at an anodic potential of SIM;900 mV, unlike the neutral pz(2)P complexes of divalent metals.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Mingchun Gao, Jose M. Ruiz, Emily Jimenez, Anna Lo, Croix J. Laconsay, James C. Fettinger, Dean J. Tantillo, Jared T. Shaw
Summary: Substrates designed for 1,4-C-H insertion to produce benzocyclobutenes underwent a unique elimination reaction, resulting in the formation of ortho-quinone dimethide (o-QDM) intermediates that further participated in Diels-Alder or hetero-Diels-Alder cycloadditions. The analogous benzylic acetals or ethers, on the other hand, bypassed the C-H insertion pathway and, after hydride transfer, underwent a de-aromatizing elimination reaction to form o-QDM at ambient temperature. The resulting dienes exhibited high diastereo- and regio-selectivity when involved in various cycloaddition reactions. This method represents a rare example of catalytic o-QDM generation without the involvement of a benzocyclobutene, and it offers a mild and ambient temperature approach to access these valuable intermediates. DFT calculations provided support for the proposed mechanism. Furthermore, this methodology was successfully applied to the synthesis of (+/-)-isolariciresinol with an overall yield of 41%.
Article
Chemistry, Multidisciplinary
Wenxing Zou, Kristian L. Mears, James C. Fettinger, Philip P. Power
Summary: Thermal Sn-C cleavage in diarylstannylene Sn(Ar-iPr4)(2) was used to generate radicals for alkyne arylstannylation. The reaction produced aryl vinyl stannylene complexes with different substituents and a known distannene.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Organic
Benjamin D. Bergstrom, Garrett Toth-Williams, Anna Lo, Jeffrey W. Toman, James. C. Fettinger, Jared T. Shaw
Summary: Polysubstituted allenes are important synthetic intermediates that offer structural complexity, modularity, and axial chirality in further transformations. We report the synthesis of tetrasubstituted allenes featuring a novel geminal acyl/alkoxy substitution, which exhibit both stability and interesting reactivity in several applications.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Kristian L. Mears, Michelle A. Kutzleb, Cary R. Stennett, James C. Fettinger, Derrick C. Kaseman, Ping Yu, Petra Vasko, Philip P. Power
Summary: The fragmentation reactions of complex [B(beta-pinane)(3)] and its analogues were studied. It was found that the stereochemistry of the terpene greatly affects the London dispersion interactions.
CHEMICAL COMMUNICATIONS
(2022)
