Article
Chemistry, Multidisciplinary
Masao Ohashi, Dan Tan, Jiayan Lu, Cooper S. Jamieson, Daiki Kanayama, Jiahai Zhou, K. N. Houk, Yi Tang
Summary: The synthesis of cis-decalin structures using [4 + 2] cycloaddition with high stereoselectivity is challenging. In this study, we investigated the biosynthetic pathway of the fungal natural product fischerin (1) and identified a novel pericyclase, FinI, which catalyzes this reaction. The cocrystal structure of FinI, a predicted O-methyltransferase, with the product and SAM provides valuable insights into the natural formation of cis-decalin.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Julia O. Strelnikova, Alexander N. Koronatov, Nikolai Rostovskii, Alexander F. Khlebnikov, Olesya Khoroshilova, Mariya A. Kryukova, Mikhail S. Novikov
Summary: The domino reaction catalyzed by Rh-2(Piv)(4) leads to the formation of N-sulfonylated (Z)-2-(2-aminovinyl)imidazoles, providing a direct and flexible access to the desired compounds.
Article
Chemistry, Organic
Yan Jiang, Hao-Jie Ma, Xue-Long Wang, Yi Yang
Summary: A Yb(OTf)(3)-catalyzed formal (4 + 3) cycloaddition reaction was successfully achieved using donor-acceptor cyclopropanes and 3-benzylideneindoline-2-thiones as reactants. Functionalized 5,10-dihydro-2H-thiepino[2,3-b]indole derivatives were synthesized with good yields and moderate to good diastereoselectivity. This reaction represents the first (4 + 3) cycloaddition of 3-benzylideneindoline-2-thiones.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Hong Zhang, Alexander J. E. Novak, Cooper S. Jamieson, Xiao-Song Xue, Shuming Chen, Dirk Trauner, K. N. Houk
Summary: Computational studies using omega B97X-D density functional theory have revealed and refined the mechanisms of unique processes in Trauner's biomimetic synthesis of preuisolactone A. The research identified an ambimodal transition state for the cycloaddition between o-quinone and hydroxy-o-quinone, leading to both (5 + 2) and (4 + 2) cycloaddition products. A new mechanism for benzilic acid rearrangement resulting in ring contraction was proposed based on the study.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Organic
Nan-Fang Mo, Ying Zhang, Zheng-Hui Guan
Summary: An asymmetric organocatalyzed three-component Povarov reaction has been developed to construct azaspirocycles. A chiral phosphoric acid catalyst with a unique structure was highly efficient in the reaction, leading to a wide range of azaspirocycles in high yields and excellent enantioselectivities. This reaction has expanded the scope of the traditional Povarov reaction.
Article
Chemistry, Organic
Gary L. Points, Christopher M. Beaudry
Summary: Substituted carbazoles are efficiently synthesized from 3-triflato-2-pyrones and alkynyl anilines, allowing for multiple substituents with complete control of regiochemistry, resulting in complex substitution patterns. This strategy can also be applied to prepare substituted bicarbazoles and related biaryls, and has been demonstrated in the synthesis of the carbazole natural product clausine C.
Article
Chemistry, Organic
Tao Wang, Wen-Bin Wang, Yan-Ming Fu, Cheng-Feng Zhu, Lan-Jun Cheng, Yang-En You, Xiang Wu, You-Gui Li
Summary: An asymmetric double oxidative [3 + 2] cycloaddition is reported, which generates highly functionalized chiral CF3-containing spiro[pyrrolidin-3,2'-oxindole] with four contiguous stereocenters stereoselectively. This method directly constructs two C-C bonds from four C(sp3)-H bonds, and it features mild conditions, broad substrate scope, and excellent functional group compatibility.
Article
Chemistry, Organic
Yan Jiang, Hao-Jie Ma, Xue-Long Wang, Yi Yang
Summary: A new compound was synthesized successfully in this study by using Yb-(OTf)(3) catalyst to react donor-acceptor cyclopropanes with sulfur-containing 4π components. The reaction showed high yields and moderate to good diastereoselectivity.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Marlene Fadel, Erick M. Carreira
Summary: The first total synthesis of (+)-pedrolide, a tigliane-derived diterpenoid featuring an unprecedented 5-5-6-6-3 carbon skeleton, was achieved. A key step in the synthesis involved the construction of the bicyclo[2.2.1]heptane core via an intramolecular cyclopentadiene-Diels-Alder cycloaddition. A norbornadiene was used as a surrogate for cyclopentadiene, and the unmasking of the cyclopentadiene was achieved through a complex Diels-Alder reaction cascade. This synthesis also provided a novel approach to a densely functionalized carane in an efficient and enantioselective manner.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Natalie J. Norman, Si Tong Bao, Lynne Curts, Tiffani Hui, Shao-Liang Zheng, Tiffany Shou, Ana Zeghibe, Izzy Burdick, Hannah Fuehrer, Adrian Huang
Summary: Inspired by crystal structures, a catalyst-free Michael reaction was designed and achieved for the preparation of N1-alkyl pyrazoles in high yield, with excellent regioselectivity. This methodology enables the synthesis of diverse substituted pyrazoles and holds significance in drug discovery. The X-ray crystal structures of the products provide valuable insights into the attractive interactions.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Natalie J. Norman, Si Tong Bao, Lynne Curts, Tiffani Hui, Shao-Liang Zheng, Tiffany Shou, Ana Zeghibe, Izzy Burdick, Hannah Fuehrer, Adrian Huang
Summary: Inspired by crystal structures, a catalyst-free Michael reaction was designed and achieved for the synthesis of N1-alkyl pyrazole with high yield and excellent regioselectivity. This methodology enables the regioselective synthesis of di-, tri-, and tetra-substituted pyrazoles in a single step, providing opportunities for late-stage functionalization. This research is of great importance to drug discovery.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
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, Physical
Kimihiko Hirao, Han-Seok Bae, Jong-Won Song, Bun Chan
Summary: Long-range-corrected (LC) functionals were investigated for their applicability to a Kohn-Sham (KS) Koopmans'-type theorem. The study found that optimally tuned LC functionals, when combined with appropriate exchange-correlation functionals, accurately predicted the ionization potential of outer valence levels, comparable to highly accurate ab initio theory. However, the accuracy was lower for inner valence and core levels. Overall, the method represents an effective one-electron orbital theory with a simple formulation and practical application.
JOURNAL OF PHYSICAL CHEMISTRY A
(2021)
Article
Chemistry, Multidisciplinary
Xiangyang Chen, Mathias Kirk Thogersen, Limin Yang, Rune F. Lauridsen, Xiao-Song Xue, Karl Anker Jorgensen, K. N. Houk
Summary: The study investigates the selectivity of [8+2] and [4+2] cycloadducts in cinchona alkaloid-catalyzed cycloaddition reactions, examining the factors influencing these pathways. It was found that the formation of final products is influenced by the reversibility of the reaction and the thermal stability of the products.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Organic
Po Yuan, Tanja Gaich
Summary: In this study, we reported a synthetic method for the enantioselective and convergent total synthesis of (+)-pepluanol A, a natural product with a structurally intriguing skeleton. The method achieved high diastereoselectivity and convergency through key reactions for constructing the unique framework.
Article
Chemistry, Physical
Takao Tsuneda, Raman Kumar Singh, Pratim Kumar Chattaraj
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2018)
Article
Chemistry, Organic
Naoyuki Shimada, Sari Urata, Kenji Fukuhara, Takao Tsuneda, Kazuishi Makino
Article
Chemistry, Physical
Takao Tsuneda, Tetsuya Taketsugu
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2018)
Article
Chemistry, Multidisciplinary
Takao Tsuneda
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2019)
Article
Chemistry, Physical
Takao Tsuneda, Takeshi Iwasa, Tetsuya Taketsugu
JOURNAL OF CHEMICAL PHYSICS
(2019)
Article
Chemistry, Multidisciplinary
Takao Tsuneda
Article
Chemistry, Organic
Ryosuke Matsubara, Akihiro Ando, Hayu Hasebe, Hojin Kim, Takao Tsuneda, Masahiko Hayashi
JOURNAL OF ORGANIC CHEMISTRY
(2020)
Article
Chemistry, Physical
Min Gao, Ben Wang, Takao Tsuneda, Andrey Lyalin, Tetsuya Taketsugu
Summary: Theoretical investigation shows that carbon-doped h-BN can catalyze the oxidation of carbon monoxide and epoxidation of ethylene by molecular oxygen at various distances from the doped carbon atoms. The results indicate that C-B/h-BN has multiple active sites and wide activation areas can be achieved with low concentrations of carbon.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Physical
Masatoshi Hasebe, Takuro Tsutsumi, Tetsuya Taketsugu, Takao Tsuneda
Summary: This study reveals a one-to-one correspondence between reaction pathways in the potential energy theory and reactive orbitals in the electronic theory. The reactive orbital energy method can accurately determine the driving mechanisms of chemical reactions and provide sophisticated interpretations of electronic motions in reactions.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2021)
Article
Chemistry, Physical
Shuichi Ebisawa, Masatoshi Hasebe, Takuro Tsutsumi, Takao Tsuneda, Tetsuya Taketsugu
Summary: The natural reaction orbital (NRO) is a new concept for analyzing chemical reactions from the electronic theory perspective, extracted from the CPSCF equation solution. The sum of squares of the singular values obtained from the CPSCF equation solution reveals peaks around transition state structures and potential energy curves, indicating a new physical meaning of transition states and asynchronous reactions. The NRO-based reaction analysis method is universal and robust, leading to universal reaction analyses based on the electronic theory.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Takao Tsuneda, Seiichiro L. Ten-no
Summary: The study investigates the initial water-oxidation reaction mechanism of the hydrated cobalt phosphate (CoPi) co-catalyst, providing insights into the formation of O-O bond and OOH. Theoretical calculations and validation demonstrate the roles of phosphate as an oxygen source and proton deliverer, leading to the spontaneous formation of an O-O bond. The study also proposes a mechanism for the subsequent formation of OOH and O2.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Takao Tsuneda, Hiroki Sumitomo, Masatoshi Hasebe, Takuro Tsutsumi, Tetsuya Taketsugu
Summary: It has been established that the reactive orbital energy theory (ROET) can theoretically reproduce the rule-based electronic theory diagrams of organic chemistry. By studying the charge transfer natures of typical organic carbon-carbon and carbon-heteroatom bond formation reactions, the ROET provides insights into the reactive orbitals and charge transferability indices. The ROET analyses also reveal the detailed orbital-based mechanisms for these reactions, explaining the pi-bond formations in acidic conditions and sigma-bond formations at alpha-carbons in basic conditions. Moreover, it is suggested that the methyl group plays a role in accepting and donating electrons in these reactions.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Masatoshi Hasebe, Takuro Tsutsumi, Tetsuya Taketsugu, Takao Tsuneda
Summary: This study compares the effects of the long-range correction (LC) and CCSD method on the total and orbital electron densities of molecules. The LC stabilizes electrons in the long-range interaction regions of kinetic energy density, while the CCSD method stabilizes electrons in the long-range interaction regions in the vertical molecular planes. The LC has a similar effect to the CCSD method on unoccupied orbitals, but differs for occupied orbitals.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2023)
Article
Chemistry, Physical
Takao Tsuneda, Yoshitaka Tateyama
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2019)
Article
Chemistry, Multidisciplinary
Takao Tsuneda, Junpei Miyake, Kenji Miyatake
Article
Chemistry, Multidisciplinary
Michal Novotny, Matus Dubecky, Frantisek Karlicky
Summary: This paper investigates the accuracy of different DFT-based computational approaches in calculating the equilibrium lattice constants and exfoliation energy of hexagonal boron nitride (h-BN). The results are compared with experiments and reference QMC calculations to evaluate the accuracy of these computational methods.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2024)
Article
Chemistry, Multidisciplinary
Luigi Crisci, Federico Coppola, Alessio Petrone, Nadia Rega
Summary: The charge transfer dynamics in asymmetrically substituted indenotetracene molecules upon photo-excitation were investigated using real-time time-dependent density functional theory simulations. The study found that the electron-donating character of the substituents affects the overall electronic energy spacing and ultrafast charge transfer dynamics.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2024)
Article
Chemistry, Multidisciplinary
Vasilii Korotenko, Hendrik Zipse
Summary: The stability of various radicals and molecules has been studied using different theoretical methods, and good correlations between theoretical calculations and experimental results have been found. The effects of hydrogen bonding interactions on the stability of oxygen-centered radicals have also been investigated.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2024)
Article
Chemistry, Multidisciplinary
Oleg Egorov, Michael Rey, Dominika Viglaska, Andrei V. Nikitin
Summary: In this work, the rovibrational energy levels of four isotopologues of methylene were calculated using a new accurate ab initio potential energy surface. The accuracy of the calculations was improved by considering scalar relativistic effects, DBOC, and high-order electronic correlations. For the first time, all available experimental rovibrational transitions were reproduced with high accuracy, without any empirical corrections.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2024)