Article
Chemistry, Multidisciplinary
Jun-Jie Tian, Ning Liu, Qi-Fei Liu, Wei Sun, Xiao-Chen Wang
Summary: This study reports the successful direct asymmetric vinylogous Mannich reactions of acyclic alpha, beta-unsaturated ketones using chiral bicyclic bisborane catalysts. The strong Lewis acidity and steric bulk of the bisborane catalysts played crucial roles in achieving high yields and selectivities.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Organic
Kalipada Jana, Isao Mizota, Armido Studer
Summary: Formal hydroperfluoroalkylation of enones is achieved through a two-step process involving conjugate hydroboration and subsequent radical perfluoroalkylation. Both reactions proceed under very mild conditions at room temperature, making the process convenient and efficient.
Article
Chemistry, Organic
Jiufeng Wu, Claire M. Young, Amy A. Watts, Alexandra M. Z. Slawin, Gregory R. Boyce, Michael Buhl, Andrew D. Smith
Summary: An enantioselective Michael addition of malonates to alpha,beta-unsaturated para-nitrophenyl esters was successfully achieved using the Lewis basic isothiourea HyperBTM as a catalyst.
Article
Chemistry, Organic
On Ying Yuen, Chau Ming So
Summary: This article discusses the recent development of gamma-arylation of alpha,beta-unsaturated carbonyl compounds and presents the ligand-controlled, site-selective alpha- and gamma-arylation of alpha,beta-unsaturated carbonyl ketones with (hetero)aryl halides. The site selectivity of the reaction can be switched by simply changing the phosphine ligand.
Article
Multidisciplinary Sciences
Can Yang, Xiaoyu Zhou, Lixing Shen, Zhuofeng Ke, Huanfeng Jiang, Wei Zeng
Summary: The authors developed a Mn(I)-catalyzed sigmatropic rearrangement of beta, gamma-unsaturated alcohols via C-C sigma bond activation. This rearrangement allows for selective reorganization of carbon skeletons, providing a strategy for the synthesis of complex structures with high atom and step economy.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Jacqueline Bitai, Alastair J. Nimmo, Alexandra M. Z. Slawin, Andrew D. Smith
Summary: A new method for the enantioselective synthesis of substituted vinylcyclopentanes has been developed using cooperative palladium and isothiourea catalysis. Functionalized cyclopentanes can be synthesized with good yields and stereocontrol by intermolecular cycloaddition between reactive intermediates.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Pei-Xue Gong, Fangning Xu, Lu Cheng, Xu Gong, Jie Zhang, Wei-Jin Gu, Wei Han
Summary: A practical iron-catalyzed domino decarboxylation-oxidation reaction has been developed for the synthesis of methyl ketones from alpha,beta-unsaturated carboxylic acids. This method is mild, operationally simple, uses ambient air as the sole oxidant, and tolerates sensitive functional groups for late-stage functionalization of complex molecules.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Organic
Qian-Qian Ma, Cheng-Jing Li, Wei-Wei Liao
Summary: An efficient method for constructing alpha-amino cyclopentanones with consecutive quaternary and ternary carbon centers is described using an alpha-iminol rearrangement and Pd-catalyzed addition reaction. The method offers high yields, excellent selectivity, and can be used to prepare high-value added compounds.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Multidisciplinary
Sanliang Li, Qiaoyu Chen, Junfeng Yang, Junliang Zhang
Summary: In this study, an efficient asymmetric gamma-arylation method for constructing chiral quaternary arylated butenolide was reported. The method showed high selectivity, good functional group tolerance, and excellent enantioselectivity. Additionally, it allowed for the facile construction of tricyclic tetrahydroindolines and tetrahydroisoquinolinones in one step.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Yao Ge, Fei Ye, Ji Yang, Anke Spannenberg, Haijun Jiao, Ralf Jackstell, Matthias Beller
Summary: A novel palladium-catalyzed cascade carbonylation is described for the direct and selective synthesis of alpha,beta-unsaturated piperidones, generating a broad range of intriguing heterocycles from easily available propargylic alcohols and aliphatic amines. The success of this transformation hinges on the catalytic cleavage of the carbon-carbon triple bond by a specific catalyst with 2-diphenylphosphinopyridine as ligand and suitable reaction conditions, with mechanistic studies pointing to the importance of branched unsaturated acid 11 as a crucial intermediate.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Gang Liu, Congcong Yin, Xuanliang Yang, Anqi Li, Minyan Wang, Xumu Zhang, Xiu-Qin Dong
Summary: A highly chemo- and enantioselective hydrogenation method for beta-sulfonyl-alpha,beta-unsaturated ketones was successfully developed, producing a variety of enantioenriched gamma-ketosulfones in good to high yields with excellent selectivities. Gram-scale asymmetric hydrogenation was carried out smoothly with high yields and selectivities. Preliminary DFT computations provided a reasonable explanation for the observed high chemoselectivity and enantioselectivity.
Article
Chemistry, Organic
Guo-Qing Jiang, Bin-Hong Han, Xian-Peng Cai, Jian-Ping Qu, Yan-Biao Kang
Summary: An iron-catalyzed direct aerobic alpha,beta-dehydrogenation of carbonyls has been reported using tert-butyl nitrite and N-hydroxyphthalimide as the co-catalyst system. This method allows for the production of a wide range of lactams, flavanones, lactone, and thiochromen-4-one in high yields without the need for extra transition metal reagents.
Article
Chemistry, Organic
Jinyi Qian, Hengyuan Zhao, Qi Gao, Lirong Chen, Yinrui Shi, Jiuling Li, Yafei Guo, Baomin Fan
Summary: In this research, a new strategy for the asymmetric carbon-phosphorus bond forming reaction using CBS catalysts via non-covalent interactions was disclosed. Various alpha,beta-unsaturated ketones showed remarkable tolerance to various diarylphosphine oxides, and a new application of oxazaborolidines in enantioselective phospha-Michael addition to alpha,beta-unsaturated ketones under mild reaction conditions was developed.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Organic
Jinyi Qian, Hengyuan Zhao, Qi Gao, Lirong Chen, Yinrui Shi, Jiuling Li, Yafei Guo, Baomin Fan
Summary: Classical proline-derived oxazaborolidines, known as CBS catalysts, have significant applications in asymmetric catalysis. This research reveals a new strategy for asymmetric carbon-phosphorus bond formation using CBS catalysts through non-covalent interactions. Various α,β-unsaturated ketones showed excellent tolerance to different diarylphosphine oxides.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Multidisciplinary
Florian Puls, Philipp Linke, Olga Kataeva, Hans-Joachim Knoelker
Summary: This paper describes a convenient method for the oxidation of olefins to ketones using Fe(dbm)(3) or a combination of iron(II) chloride and neocuproine as catalysts and phenylsilane as an additive. The reactions are efficient and have a high yield and selectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Koki Kise, Shota Ooi, Hayate Saito, Hideki Yorimitsu, Atsuhiro Osuka, Takayuki Tanaka
Summary: Peripherally pi-extended corannulenes with quintuple azahelicene units were prepared and their dynamic behaviors were studied. Analysis revealed that the structural isomers can interchange in solution, depending on steric congestion, and the co-existing moieties influence the conformational dynamics, reducing activation energy barriers for isomerization.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Qian Zhang, Shijun Deng, Dong Li, Jun Shimokawa, Hideki Yorimitsu
Summary: A facile and efficient AgF-mediated electrophilic amination of alkoxyarylsilanes with azodicarboxylates has been developed. The reaction proceeds under green and mild conditions, generating aryl hydrazines.
CHEMISTRY-AN ASIAN JOURNAL
(2022)
Article
Biochemistry & Molecular Biology
Kazuhira Miwa, Shinobu Aoyagi, Takahiro Sasamori, Shogo Morisako, Hiroshi Ueno, Yutaka Matsuo, Hideki Yorimitsu
Summary: The reduction of fullerene (C-60) with sodium dispersion in the presence of an excess amount of dipropyl sulfate yields highly propylated fullerene, C-60(nC(3)H(7))(n) (max. n = 24), with C-60(nC(3)H(7))(20) being predominantly generated as indicated by mass spectrometry.
Article
Chemistry, Organic
Shuo Wang, Atsushi Kaga, Takashi Kurogi, Hideki Yorimitsu
Summary: In this study, treatment of arylcyclopropanecarboxamides with a sodium dispersion in the presence of methoxypinacolborane as a reduction-resistant electrophile was investigated. The results showed that the reaction led to the reductive cleavage of the cyclopropane ring followed by instant trapping with the boron electrophile, resulting in the formation of enolates of gamma-aryl-gamma-borylalkanamides. The enolates could further react with a different electrophile to produce the corresponding a-substituted amides with anti selectivity.
Article
Chemistry, Organic
Shunsuke Koyama, Fumiya Takahashi, Hayate Saito, Hideki Yorimitsu
Summary: Treatment of alkenyl carbamates with sodium dispersion and a co-existing boron electrophile leads to the formation of alkenylboronates through the reductive cleavage of the vinylic C-O bond, facilitated by the instant trapping of reactive organosodium species.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Organic
Hiroki Yamagishi, Fuyuki Harata, Jun Shimokawa, Hideki Yorimitsu
Summary: In this study, we introduce sodium diphenylsilylsilanolates as new stable and convenient silylating reagents, which can be synthesized from chlorosilanes. The new reagents exhibit the ability to deliver various silyl groups in palladium-catalyzed silylation of aryl bromides, regardless of the steric and electronic properties of the silyl groups to be transferred.
Article
Chemistry, Multidisciplinary
Shuo Wang, Igor Larrosa, Hideki Yorimitsu, Gregory J. P. Perry
Summary: The potassium salts of carboxylic acids are developed as efficient carboxylating agents through CO2 exchange. These carboxylates function as a combined source of CO2 and base/metalating agent, making them dual-function reagents. By using the salt of a commercially available carboxylic acid, this protocol provides a convenient and practical alternative to using CO2 gas or organometallic reagents, without the need for pressurized containers or strictly inert conditions. The reaction is mild, transition metal-free, and exhibits a wide range of substrate compatibility. The strategy showcased the ability to isotopically label biologically important molecules using low amounts of labeled CO2.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Fumiya Takahashi, Hideki Yorimitsu
Summary: In this study, regio- and stereoselective synthesis of Tetraarylethylenes (TAEs) was achieved through sodium-promoted reductive anti-1,2-dimagnesiation of alkynes and palladium-catalyzed arylation. This method not only enables the synthesis of diarylacetylenes, but also allows for the synthesis of alkyl aryl acetylenes, expanding the range of possible TAEs.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Kazuhira Miwa, Shinobu Aoyagi, Toru Amaya, Takahiro Sasamori, Shogo Morisako, Takashi Kurogi, Hideki Yorimitsu
Summary: The curved and π-conjugated surface of bowl-shaped corannulene has been multiply methylated through in-situ iterative reduction/methylation sequences, resulting in exo-di-, -tetra-, and -hexamethylated corannulenes. Various analytical techniques have been used to reveal the molecular structures of the multimethylated corannulenes and the sequence of the multimethylation. This work has the potential to contribute to the controlled synthesis and characterization of multifunctionalized fullerenes.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Organic
Tomohiko Sato, Somnath N. Karad, Jun Shimokawa, Hideki Yorimitsu
Summary: The regioselective anti-silyllithiation of propargylic amines provides an efficient route for the synthesis of alkenylsilanes. The reaction involves the formation of a stable alkenyllithium intermediate through intramolecular coordination of the nitrogen functional group. After treatment with an electrophile, the alkenyllithium intermediate is functionalized to yield tetrasubstituted allylic amines bearing a beta-silicon substituent.
Article
Chemistry, Physical
Hiroki Yamagishi, Jun Shimokawa, Hideki Yorimitsu
Summary: The multifaceted implementation of silanols in organic synthesis is reviewed in terms of advances in transition metal-catalyzed reactions. The major properties of silanols are summarized, including their use as nucleophiles to serve as bulky surrogates for water, as temporary ligands to control the regioselectivity of metal-catalyzed reactions, and as coupling partners for transferring functional groups. These summaries provide opportunities for future developments in silanol chemistry.
Article
Chemistry, Organic
Ziwei Zhang, Fumiya Takahashi, Takashi Kurogi, Hideki Yorimitsu
Summary: The preparation of vinylic lithium reagents from vinylic halides is common in organic synthesis, but not always easy. This study proposes a new method using silyl enolates of alkyl aryl ketones, which provides readily available and efficient vinylic lithium species. The reductive transformation of electron-rich silyl enolates has significant potential for various applications in organic synthesis, serving as an alternative to the Shapiro reaction.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Sara Suzuki, Soni Aman Govind, Kosuke Imamura, Hideki Yorimitsu, Hiroshi Shinokubo, Masahiro Higashi, Hirofumi Sato
Summary: The radical cyclization reaction in aqueous environment by Yorimitsu et al. was reexamined using the RISM-SCF-cSED method, a hybrid approach combining quantum chemistry and statistical mechanics for molecular liquids. The difference in barrier height between the forward reaction from the intermediate E-rot, the cyclization step, and the backward reaction is crucial for the reaction yield. By considering the effect of hydrogen bonding through the RISM theory, it was found that the barrier height for the forward reaction is lower, particularly in water. In other words, accounting for microscopic solvation effects clearly elucidates the disparity between water and DMSO solvents, explaining the significant acceleration of the reaction in the aqueous environment.
CHEMICAL PHYSICS LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Yiyuan Jiang, Hideki Yorimitsu
Summary: This study demonstrates the efficient generation of 1,4-organodilithiums through the reduction of styrenes with lithium arenide in flow microreactors. The use of a flow reactor with fast mixing is essential for achieving high efficiency and selectivity, which are low under batch conditions. The resulting 1,4-organodilithiums can react with various electrophiles to yield precursors for useful yet less accessible cyclic structures.
Article
Chemistry, Multidisciplinary
Hiroki Yamagishi, Kenshiro Hitoshio, Jun Shimokawa, Hideki Yorimitsu
Summary: This study extends the utility of sodium silylsilanolates as competent precursors of silylcoppers, and the mechanistic studies through DFT calculation reveal the mechanism of copper silylsilanolate transforming into silylcopper.