More Like this

1. A metal-free strategy to construct fluoroalkyl–olefin linkages using fluoroalkanes

   https://doi.org/10.1039/D3SC05616C  

   Chakrabarti, Kaushik; Wade_Wolfe, Michael M; Guo, Shuo; Tucker, Joseph W; Lee, Jisun; Szymczak, Nathaniel K (January 2024, Chemical Science)

   We report a metal-free strategy to access fluoroalkyl–olefin linkages from RCF₂H (R = aryl, H, F and fluoroalkyl) precursors and vinyl-pinacol boronic ester (BPin) reagents. 

   more » « less
2. Hypervalent Iodine‐Mediated Azidation Reactions

   https://doi.org/10.1002/ejoc.202200754  

   Mironova, Irina_A; Kirsch, Stefan_F; Zhdankin, Viktor_V; Yoshimura, Akira; Yusubov, Mekhman_S (September 2022, European Journal of Organic Chemistry)

   Abstract Organic azides have found wide application in various fields of science and technology. This review summarizes recently developed approaches to the direct, one‐step synthesis of diverse organic azides utilizing hypervalent iodine reagents. The first part of review deals with the azidation using unstable azidoiodinanes generatedin situfrom common hypervalent iodine reagents (such as diacetoxyiodobenzene or iodosylbenzene) and a source of azide anion (TMSN₃or NaN₃). The second part of review is dedicated to the application of stable azidobenziodoxoles as useful azidating reagents that allow selective direct azidation of C−H bonds or double carbon‐carbon bonds under mild reaction conditions. The use of azidobenziodoxoles eliminates the main disadvantages of the traditional approaches to organic azides, such as the need in pre‐functionalization of organic substrates and harsh reaction conditions. Synthetic application of azidobenziodoxoles made possible direct selective azidation of a plethora of organic substrates including complex molecules at the late synthetic stage. 

   more » « less
3. Significant Polar Comonomer Enchainment in Zirconium‐Catalyzed, Masking Reagent‐Free, Ethylene Copolymerizations

   https://doi.org/10.1002/anie.201902042  

   Chen, Jiazhen; Motta, Alessandro; Wang, Binghao; Gao, Yanshan; Marks, Tobin J. (April 2019, Angewandte Chemie International Edition)

   Abstract In principal, the direct copolymerization of ethylene with polar comonomers should be the most efficient means to introduce functional groups into conventional polyolefins but remains a formidable challenge. Despite the tremendous advances in group 4‐centered catalysis for olefin polymerization, successful examples of ethylene + polar monomer copolymerization are rare, especially without Lewis acidic masking reagents. Here we report that certain group 4 catalysts are very effective for ethylene + CH₂=CH(CH₂)_nNR₂copolymerizations with activities up to 3400 Kg copolymer mol⁻¹‐Zr h^‐1 atm^‐1, and with comonomer enchainment up to 5.5 mol % in the absence of masking reagents. Group 4 catalyst‐amino‐olefin structure–activity‐selectivity relationships reflect the preference of olefin activation over free amine coordination, which is supported by mechanistic experiments and DFT analysis. These results illuminate poorly understood facets of d⁰metal‐catalyzed polar olefin monomer copolymerization processes. 

   more » « less
4. Diisobutylammonium triphenyl(2-thiolatoacetato-κ ² O , S )stannate(IV)

   https://doi.org/10.1107/S2414314624007429  

   Song, Xueqing; Yeibyo, Woldegebriel; Li, William; Pike, Robert D (August 2024, IUCrData)

   Crystals of the title salt, (C₈H₂₀N)[Sn(C₆H₅)₃(C₂H₂O₂S)], comprise diisobutylammonium cations and mercaptoacetatotriphenylstannate(IV) anions. The bidentate binding mode of the mercaptoacetate ligand gives rise to a five-coordinated, ionic triphenyltin complex with a distortedcis-trigonal–bipyramidal geometry around the tin atom. In the crystal, charge-assisted ammonium-N—H...O(carboxylate) hydrogen-bonding connects two cations and two anions into a four-ion aggregate. Two positions were resolved for one of the phenyl rings with the major component having a site occupancy factor of 0.60 (3). 

   more » « less
5. Recent Progress in Synthetic Applications of Cyclic Hypervalent Iodine(III) Reagents

   https://doi.org/10.1002/adsc.202300275  

   Yoshimura, Akira; Saito, Akio; Zhdankin, Viktor_V (May 2023, Advanced Synthesis & Catalysis)

   Abstract Hypervalent iodine compounds have found broad application in modern organic chemistry as reagents and catalysts. Cyclic hypervalent iodine reagents based on the benziodoxole heterocyclic system have higher stability compared to their acyclic analogues, which makes possible the preparation and safe handling of the reagents with special ligands such as azido, cyano, and trifluoromethyl groups. Numerous iodine‐substituted benziodoxole derivatives have been prepared and utilized as reagents for transfer of the substituent on hypervalent iodine to organic substrate. Reactions of these reagents with organic substrates can be performed under metal‐free conditions, in the presence of transition metal catalysts, or using photocatalysts under photoirradiation conditions. In this review, we focus on the most recent synthetic applications of cyclic hypervalent iodine(III) reagents with the following ligands: N₃, NHR, CN, CF₃, SCF₃, OR, OAc, ONO₂, and C(=N₂)CO₂R. The review covers literature published mainly in the last 5 years. 

   more » « less