Review
Chemistry, Multidisciplinary
Dilruba A. Popy
Summary: 2-thiazolines are important structural motifs in pharmaceuticals, agrochemicals and chemistry, and their synthesis has been widely investigated. Transition-metal catalysts have played significant roles in synthesizing stereochemically important N-heterocycles, but challenges in stereochemistry and asymmetric processes still remain. Further research is needed to address the scope, limitations and future prospects in the metal mediated synthetic strategies of 2-thiazolines.
Article
Chemistry, Multidisciplinary
Tobias Wagener, Lukas Lueckemeier, Constantin G. Daniliuc, Frank Glorius
Summary: This study successfully demonstrates the synthesis of sought-after, enantioenriched delta-lactams through an interrupted hydrogenation mechanism using oxazolidinone-substituted pyridines and water.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Chenxiao Qian, Pengfei Li, Jianwei Sun
Summary: A catalytic enantioselective variant of oxidative rearrangement of indoles to access oxindoles has been developed using chiral phosphoric acid catalysis, providing a rapid access to a range of enantioenriched spirooxindoles with high enantioselectivity controlled by dynamic kinetic resolution.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Zhi-Xin Zhang, Xuan Wang, Jia-Tian Jiang, Jie Chen, Xin-Qi Zhu, Long-Wu Ye
Summary: In the past decade, catalytic asymmetric dearomatization of indoles and alkynes has been widely studied as an attractive and alternative strategy for the efficient synthesis of valuable chiral polycyclic indolines. However, most of these reactions have been limited to transition-metal catalysts, with few reports on chiral Bronsted acid catalysis. Here, we present a chiral phosphoric acid-catalyzed asymmetric dearomatization of indolyl ynamides via direct activation of alkynes. This metal-free method allows for the practical and atom-economical construction of a range of valuable chiral polycyclic indolines with moderate to good yields and high enantioselectivities.
CHINESE CHEMICAL LETTERS
(2023)
Review
Chemistry, Applied
Yong-Xing Song, Da-Ming Du
Summary: The aza-Michael addition cascade reaction is an important synthetic method for constructing functionalized C-N bonds, widely used in the synthesis of chiral drugs, intermediates, and natural products. This review highlights recent developments in asymmetric synthesis, including various types of aza-Michael addition triggered cascade reactions, reaction mechanisms, and derivatization experiments.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Feng-Lin Hong, Chong-Yang Shi, Pan Hong, Tong-Yi Zhai, Xin-Qi Zhu, Xin Lu, Long-Wu Ye
Summary: In this study, a copper-catalyzed asymmetric cascade cyclization/[1,2]-Stevens-type rearrangement was reported to efficiently assemble a variety of valuable chiral chromeno[3,4-c]pyrroles bearing a quaternary carbon stereocenter with generally moderate to good yields and excellent enantioselectivities (up to 99% ee). Notably, this protocol represents the first example of catalytic asymmetric [1,2]-Stevens-type rearrangement based on alkynes and the first asymmetric formal carbene insertion into the Si-O bond.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Editorial Material
Chemistry, Physical
Svetlana B. Tsogoeva, Guangbin Dong, Lutz Ackermann
Summary: This Special Collection discusses the latest strategies and progress in ring synthesis, including catalytic domino reactions and one-pot processes. Contributions cover transition-metal catalysis, organocatalysis, nanocatalysis, and photoredox catalysis for preparing carbocyclic and heterocyclic compounds.
Article
Chemistry, Applied
Tao Wang, Bo Huang, You-Qing Wang
Summary: Using chiral phosphoric acids as organocatalysts, a formal asymmetric (4+2) cycloaddition of 3-methylene isoindolinone and in situ-generated ortho-quinone methide substrates is achieved. This reaction allows the construction of spiro chroman-isoindolinones containing spiro-N,O-heterocycles with high enantioselectivity, with a broad substrate scope.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Liam A. McLean, Matthew W. Ashford, James W. B. Fyfe, Alexandra M. Z. Slawin, Andrew G. Leach, Allan J. B. Watson
Summary: We have reported a method for synthesizing chiral vicinal chloroamines through asymmetric protonation using chiral Bronsted acids. The process is highly selective and the origins of asymmetry and the effects of catalyst substitutions have been clarified by DFT calculations. Additionally, we have demonstrated the utility of this method in synthesizing a wide range of heterocycle-substituted aziridines and vicinal diamines.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Vibha V. Kanale, Christopher Uyeda
Summary: Cobalt catalysts facilitate highly enantioselective ring-opening reactions of 2,5-dihydrofurans using vinylidenes. The resulting products are acyclic organozinc compounds, capable of further functionalization with an electrophile. The proposed mechanism involves the formation of a cobalt vinylidene species that adds to the alkene via a [2+2]-cycloaddition pathway, followed by ring-opening through outer-sphere & beta;-O elimination assisted by a ZnX2 Lewis acid. DFT models explain the observed stereochemical outcome by suppressing competing inner-sphere syn & beta;-H and & beta;-O elimination pathways due to the geometric constraints of the metallacycle intermediate. Cobalt catalysts also promote enantioselective ring-opening reactions of unstrained heterocycles via reductive addition of 1,1-dichloroalkenes. The resulting products are acyclic homoallylic alcohols with a vinylzinc motif, which can be further modified with an electrophile. Mechanistic studies suggest that the ring-opening occurs through outer-sphere & beta;-O elimination facilitated by a Zn(II) Lewis acid.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Juan Camilo Arango-Daza, Carles Lluna-Galan, Luis Izquierdo-Aranda, Jose R. Cabrero-Antonino, Rosa Adam
Summary: A heterogeneous catalytic system for the acceptorless dehydrogenative condensation between N,N'-disubstituted ureas and 1,2-diols to produce imidazolones was developed. The designed palladium nanoaggregates on an alumina matrix showed good activity and selectivity, with wide applicability and moderate to good yields. Mechanistic studies and characterization were performed, revealing the key factors for the catalyst's activity. Furthermore, a Pd-Zn cooperation effect was described, and bimetallic materials were also designed and characterized properly.
Review
Chemistry, Multidisciplinary
Shuke Wu, Radka Snajdrova, Jeffrey C. Moore, Kai Baldenius, Uwe T. Bornscheuer
Summary: Biocatalysis is widely used as an alternative to chemical catalysis in various fields, with enzymes playing a key role in organic synthesis, particularly in the production of chiral compounds for pharmaceuticals and flavors. Biocatalysts are also utilized on a large scale for the production of specialty and bulk chemicals. This review focuses on scalable chemical production using enzymes, discussing opportunities, limitations, and emerging enzyme classes through illustrative examples.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Bo-Han Zhu, Ying-Qi Zhang, Hao-Jin Xu, Long Li, Guo-Cheng Deng, Peng-Cheng Qian, Chao Deng, Long-Wu Ye
Summary: An efficient copper-catalyzed tandem alkyne hydration/intramolecular Mannich reaction has been investigated for the synthesis of valuable compounds. This method allows the efficient synthesis of 3,4-dihydro-2-quinolones with high regio-, diastereo-, and enantioselectivity.
Review
Biochemistry & Molecular Biology
Olga Bakulina, Anna Inyutina, Dmitry Dar'in, Mikhail Krasavin
Summary: This review summarizes recent developments in multicomponent reactions of diazo compounds, analyzing the role of diazo reagents and the type of interaction between components. In contrast to previous reviews mostly focused on metal catalyzed transformations, this work covers a substantial amount of organocatalytic or catalyst-free methodologies.
Review
Chemistry, Multidisciplinary
Kangkang Sun, Hongbin Shan, Guo-Ping Lu, Chun Cai, Matthias Beller
Summary: N-heterocycles are important building blocks for organic chemistry and the fine-chemical industry. Recent attention has been given to the use of catalytic borrowing hydrogen and acceptorless dehydrogenative coupling reactions for their synthesis. Metal-based heterogeneous catalysts have been developed to achieve these transformations with good yields and selectivity, overcoming issues with product separation and catalyst reusability.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
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
Physics, Multidisciplinary
Jackson R. Badger, Yundi Quan, Matthew C. Staab, Shuntaro Sumita, Antonio Rossi, Kasey P. Devlin, Kelly Neubauer, Daniel S. Shulman, James C. Fettinger, Peter Klavins, Susan M. Kauzlarich, Dai Aoki, Inna M. Vishik, Warren E. Pickett, Valentin Taufour
Summary: Unconventional superconductors have Cooper pairs with lower symmetries compared to conventional superconductors. This article demonstrates that the time-reversal symmetry breaking in the superconductor LaNiGa2 is enabled by its previously unknown topological electronic band structure. These unique topological features allow LaNiGa2 to break time-reversal symmetry in the absence of other typical ingredients, providing a pathway for identifying a new type of unconventional superconductors based on nonsymmorphic symmetries.
COMMUNICATIONS PHYSICS
(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)
