Article
Chemistry, Multidisciplinary
Qing-Qing Han, De-Mao Chen, Zu-Li Wang, Yuan-Yuan Sun, Shao-Hui Yang, Jing-Cheng Song, Dao-Qing Dong
Summary: An efficient and facile method for C-H amination of quinoxalinones with heteroaromatic amines under metal-free conditions has been described. The desired products with various groups were obtained with moderate to high yields in the presence of hypervalent PIDA reagent.
CHINESE CHEMICAL LETTERS
(2021)
Article
Chemistry, Organic
Chenyang Wang, Peng Shi, Carsten Bolm
Summary: In this study, dichloro- and dibromomethane were utilized as halogen sources to convert NH-sulfoximines to N-halo derivatives, using an in situ formed sulfoximidoyl-containing hypervalent iodine reagent under visible light. The reactions were carried out in air without the need for catalysts or additives, and the products were obtained in good to excellent yields.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Organic
Xia Wang, Peng Yang, Bo Hu, Qian Zhang, Dong Li
Summary: A novel transformation of primary amides to secondary amides was developed using hypervalent iodine reagents, promoting a Hofmann-type rearrangement to generate an isocyanate intermediate which was then trapped by a carboxylic acid from the same reagent to provide the corresponding secondary amides. This method not only offers an easy and efficient route for synthesizing secondary amides from primary amides, but also reveals novel reactivities of hypervalent iodine reagents.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Lachlan Barwise, Jason D. Bennetts, Keith F. White, Jason L. Dutton
Summary: The synthesis and crystallographic characterization of NO2-C6H4-I(NTf2)(2) (NTf2 = bistriflimide) are reported. Experimental results demonstrate that this compound is capable of performing oxidation reactions that ArI(OTf)2 is unable to. Theoretical analysis indicates that Ar-I(NTf2)(2) is the most oxidizing compound among the known ArIL2 class of compounds, and it may also be the most oxidizing compound among the practically possible compounds in this class.
CHEMICAL COMMUNICATIONS
(2023)
Review
Chemistry, Organic
Yang Zhifang, Cheng Yifu, Zhang Beibei, Dong Yunyi, Han Chi, Du Yunfei
Summary: This review discusses the development and application of hypervalent-iodine chemistry, with a focus on oxidative rearrangement reactions catalyzed by hypervalent iodine reagents. These reactions have wide application prospects and are of great significance to the field of organic research.
CHINESE JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Tomohiro Maegawa, Ryohei Oishi, Ayumi Maekawa, Kazutoshi Segi, Hiromi Hamamoto, Akira Nakamura, Yasuyoshi Miki
Summary: We investigated the reaction of ketoximes with hypervalent iodine reagents and found that a combination of PhI(OAc)(2) and BF3 center dot Et2O promoted the Beckmann rearrangement of ketoximes, forming the corresponding amides. Additionally, we determined that the Beckmann rearrangement is preceded by the in situ acetylation of the hydroxy group of the ketoxime, and confirmed that the acetylated ketoxime undergoes the Beckmann rearrangement with BF3 center dot Et2O. We also discovered that the reaction of ketoximes with Koser's reagent [PhI(OH)OTs] in the presence of tetrahydrofuran resulted in hydrolysis, yielding the corresponding ketones in high yields at room temperature.
SYNTHESIS-STUTTGART
(2022)
Article
Chemistry, Multidisciplinary
Abhaya Kumar Mishra, Romain Tessier, Durga Prasad Hari, Jerome Waser
Summary: In this study, functionalization of cysteine residues with lipophilic alkynes using amphiphilic ethynylbenziodoxolone reagents (EBXs) was successfully achieved under physiological conditions without the need for organic co-solvent or removal of oxygen. The transformation led to a significant increase of peptide lipophilicity and worked for various thiol-containing compounds and peptides of different lengths. His(6)-Cys-Ubiquitin was also alkynylated under these conditions, demonstrating the versatility of this method.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Review
Chemistry, Organic
Chunngai Hui, Andrey P. Antonchick
Summary: This study introduces a new reactive electrophilic aminating reagent, iodonitrene, which can transfer NH-group directly to nucleophilic atoms and has led to the development of new reactions. The application of iodonitrene has promising prospects, although there are current limitations.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Multidisciplinary
Alisa S. Sunagatullina, Andreas Hess, Alexander Kremsmair, Yifan Li, Yi-Hung Chen, Paul Knochel
Summary: We present a novel electrophilic amination method for primary, secondary, and tertiary alkyl, benzylic, and allylic zinc and magnesium organometallics using O-2,4,6-trimethylbenzoyl hydroxylamines (O-TBHAs) with yields ranging from 52-99%. These O-TBHAs exhibit excellent long-term stability and can be conveniently synthesized from various highly functionalized secondary amines through a three-step procedure. The amination reactions demonstrate remarkable chemoselectivity without the need for transition-metal catalysts, and are typically completed within 1-3 hours at 25 degrees Celsius. Furthermore, this electrophilic amination process enables the synthesis of enantioenriched tertiary amines (up to 88% ee) using optically enriched secondary alkylmagnesium reagents of the type s-AlkylMgCH(2)SiMe(3).
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Inorganic & Nuclear
Huai-Ming Li, Guan-Dong Li, Jun-Yu Li, Teng Zhang
Summary: An iodine-functionalized metal-organic framework (MOF), UiO-68-I, was synthesized and showed good catalytic activity for dibromination of alkenes and alkynes. Its low catalyst loading of 1% allows for efficient recycling and recovery. Mechanistic studies suggest that UiO-68-I may accelerate the reaction by triggering the formation of molecular bromine through a radical intermediate. The activity and stability of UiO-68-I surpasses previous reports on organoiodine catalysts, highlighting the potential of iodine-functionalized MOFs as recyclable heterogeneous hypervalent iodine reagents or catalysts.
INORGANIC CHEMISTRY COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Mattis Damrath, Lucien D. Caspers, Daniel Duvinage, Boris J. Nachtsheim
Summary: Two simple methods for synthesizing O- and N-bridged diaryliodonium triflates are described. Different derivatizations were applied to demonstrate their usefulness as building blocks and to gain a deeper understanding of their general reactivity.
Article
Chemistry, Organic
Chenyang Wang, Yongliang Tu, Ding Ma, Chaimae Ait Tarint, Carsten Bolm
Summary: The reaction between [Bis(difluoroacetoxy)iodo]benzene and NH-sulfoximines produces hypervalent iodine(III) reagents, which can transfer difluoroacetoxy and sulfoximidoyl groups to styrenes with high regioselectivity under photocatalysis. Mechanistic investigations suggest the involvement of radicals and highlight the importance of the difluoroacetoxy group in the iodine reagent.
Article
Chemistry, Organic
Julien Borrel, Jerome Waser
Summary: In this study, a simplified synthesis method for generating Ethynylbenziodoxolones (EBXs) in one pot and directly applying them to substrate functionalization was reported. By bypassing the mandatory isolation and purification steps, this approach led to a more efficient synthesis and successful application in various transformations to obtain a diverse range of alkynylated products.
Article
Chemistry, Multidisciplinary
Lu Wang, Fuxing Shi, Chaorong Qi, Wenjie Xu, Wenfang Xiong, Bangxiong Kang, Huanfeng Jiang
Summary: The study presents a stereodivergent synthesis of beta-iodoenol carbamates through a photocatalytic three-component coupling, demonstrating the potential synthetic utility and practicality of the method. Additionally, this strategy could provide a general method for stereodivergent construction of trisubstituted alkenes, representing a fascinating challenge in the field of organic chemistry research.
Article
Chemistry, Physical
Tian-Yu Sun, Kai Chen, Qihui Lin, Tingting You, Penggang Yin
Summary: The reaction pattern of hypervalent iodine reagents involves hypervalent twist followed by reductive elimination, and studying the mechanism of hypervalent twist can guide experiments effectively. Previous research has identified two types of hypervalent twist models, namely apical twist and equatorial twist. This study successfully identified Togni II's isomerization pathway via equatorial twist, suggesting that different hypervalent twist models should be considered to predict the correct reaction mechanisms.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Organic
Kensuke Kiyokawa, Takaya Nagata, Satoshi Minakata
SYNTHESIS-STUTTGART
(2018)
Article
Chemistry, Organic
Kensuke Kiyokawa, Daichi Okumatsu, Satoshi Minakata
BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY
(2018)
Article
Chemistry, Multidisciplinary
Kensuke Kiyokawa, Daichi Okumatsu, Satoshi Minakata
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2019)
Article
Chemistry, Multidisciplinary
Kensuke Kiyokawa, Shunpei Kainuma, Satoshi Minakata
Article
Chemistry, Organic
Kensuke Kiyokawa, Satoshi Minakata
Article
Chemistry, Organic
Yuuki Kiyosu, Shino Tanaka, Sota Okumura, Kensuke Kiyokawa, Satoshi Minakata
Summary: The synthesis of a series of fused diaziridines, which are difficult to access by existing methods, was achieved by the reaction of cyclic secondary amines with p-toluenesulfonamide in the presence of N-bromosuccinimide (NBS) and a suitable base. An alternative method using N-bromo-N-sodio-ptoluenesulfonamide (bromamine-T) in the presence of a catalytic amount of CF3CO2H for the synthesis of fused diaziridines is also reported. This oxidation system enables the efficient in situ formation of the key intermediates, N-bromoamines and N-bromosulfonamides.
SYNTHESIS-STUTTGART
(2021)
Article
Chemistry, Multidisciplinary
Kensuke Kiyokawa, Keisuke Jou, Satoshi Minakata
Summary: A new transition-metal-free method using t-BuOI or NIS was reported for the construction of 1,3-diamine structures, enabling secondary non-benzylic and tertiary C-H amination reactions to proceed. Mechanistic investigations revealed different pathways for amination reactions using t-BuOI or NIS.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Organic
Kensuke Kiyokawa, Naruyo Urashima, Satoshi Minakata
Summary: In this study, a method for the C3 cyanoalkylation of indoles using cyanohydrins in the presence of a B(C6F5)(3) catalyst was reported. Mechanistic investigations revealed the unique reactivity of the B(C6F5)(3) catalyst in promoting the decomposition of cyanohydrins. Additionally, a catalytic three-component reaction using indoles, aldehydes, and acetone cyanohydrin was developed for the synthesis of various types of indole-3-acetonitrile derivatives.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Kensuke Kiyokawa, Miu Ishizuka, Satoshi Minakata
Summary: This study reports on the intermolecular oxycyanation of alkenes using p-toluenesulfonyl cyanide (TsCN) and tris(pentafluorophenyl)borane (B(C6F5)3) as a catalyst, which affords products containing a sulfinyloxy group and a cyano group at the vicinal position. The reaction exhibits stereospecific syn-addition and a broad substrate scope with good functional group tolerance. Mechanistic investigations reveal that the reaction proceeds through an unprecedented stereospecific mechanism involving electrophilic cyanation of alkenes and coordination of the cyano group to the boron center.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Kensuke Kiyokawa, Ikumi Noguchi, Takaya Nagata, Satoshi Minakata
Summary: In this study, we present a bromocyanation reaction of styrene derivatives using cyanogen bromide in the presence of tris(pentafluorophenyl)borane as a Lewis acid catalyst. The reaction proceeds through a stereospecific syn-addition and provides a straightforward approach to beta-bromonitriles.
Article
Chemistry, Organic
Kensuke Kiyokawa, Ikumi Noguchi, Takaya Nagata, Satoshi Minakata
Summary: In this study, we demonstrate the bromocyanation of styrene derivatives with cyanogen bromide using tris(pentafluorophenyl)borane as a Lewis acid catalyst. This protocol enables a stereospecific syn-addition and provides an accessible route to beta-bromonitriles.
Article
Chemistry, Organic
Kensuke Kiyokawa, Shogo Nakamura, Satoshi Minakata
Summary: The transition-metal-free aziridination of alkenes with sulfamate esters in the presence of tert-butyl hypoiodite (t-BuOI) offers a practical and environmentally benign method for the synthesis of valuable aziridine compounds, usable in both intra- and intermolecular reactions.
Article
Chemistry, Multidisciplinary
Kensuke Kiyokawa, Shogo Nakamura, Keisuke Jou, Kohji Iwaida, Satoshi Minakata
CHEMICAL COMMUNICATIONS
(2019)
Article
Chemistry, Multidisciplinary
Kensuke Kiyokawa, Shotaro Hata, Shunpei Kainuma, Satoshi Minakata
CHEMICAL COMMUNICATIONS
(2019)
Review
Chemistry, Organic
Kensuke Kiyokawa, Satoshi Minakata
JOURNAL OF SYNTHETIC ORGANIC CHEMISTRY JAPAN
(2018)
