31236-94-9Relevant articles and documents
One-pot synthesis of α-bromo- and α-azidoketones from olefins by catalytic oxidation with in situ-generated modified IBX as the key reaction
Chandra, Ajeet,Parida, Keshaba Nanda,Moorthy, Jarugu Narasimha
, p. 5827 - 5832 (2017/09/09)
Simple one-pot protocols for the syntheses of α-bromoketones and α-azidoketones starting from olefins have been developed by employing catalytic oxidation of the intermediary bromohydrins with in situ-generated modified IBX as the key reaction. The improved procedure involves initial formation of bromohydrin by the reaction of olefin with NBS in acetonitrile-water mixture (1:1) at rt followed by oxidation with in situ-generated 3,4,5,6-tetramethyl-2-iodoxybenzoic acid (TetMe-IBX), produced in catalytic amounts from 3,4,5,6-tetramethyl-2-iodobenzoic and Oxone. α-Bromoketones are further converted in the same pot to the corresponding α-azidoketones using NaN3/NaHCO3. The one-pot conversions are versatile for a variety of olefins that include cyclic as well as acyclic aliphatic olefins and electron-rich and electron-deficient styrenes. Chemoselective bromohydroxylation of electron-rich double bond and subsequent oxidation to the α-bromoketone is demonstrated for a substrate that contains both electron-rich and deficient double bonds.
A Simple and Efficient Method for the Preparation of α-Halogenated Ketones Using Iron(III) Chloride and Iron(III) Bromide as Halogen Sources with Phenyliodonium Diacetate as Oxidant
Tang, Shi-Zhong,Zhao, Wenshuang,Chen, Tao,Liu, Yang,Zhang, Xiao-Ming,Zhang, Fu-Min
supporting information, p. 4177 - 4183 (2017/12/18)
α-Halogenated ketones are both unique structure moieties existing in biologically natural products and valuable synthetic intermediates for the preparation of functional molecules. An efficient and scalable method for the preparation of α-halogenated ketone using iron (III) chloride and iron (III) bromide as halogen sources with phenyliodonium diacetate as oxidant has been developed, featuring mild reaction conditions, environmentally friendly reagents, and wide substrate scope. Notably, the three-step synthesis of drug prasugrel was achieved using this developed method as a key step with 30% yield on gram-scale. Additionally, the reaction mechanism involving chloride cation was proposed based on some preliminary control experiments. (Figure presented.).
Halogen and chalcogen cation pools stabilized by DMSO. Versatile reagents for alkene difunctionalization
Ashikari, Yosuke,Shimizu, Akihiro,Nokami, Toshiki,Yoshida, Jun-Ichi
supporting information, p. 16070 - 16073 (2013/11/19)
Halogen and chalcogen cations (X+ = Br+, I +, ArS+, and ArSe+) were generated by low-temperature electrochemical oxidation in the presence of dimethyl sulfoxide (DMSO) and were accumulated in the solution. DFT calculations indicated that DMSO stabilizes these cations by coordination. The complexes of I+ with one and two DMSO molecules were observed by cold-spray-ionization MS analyses. The stability of the resulting cation pools of X+ increased in the order of Br+ + + +, which could be explained in terms of the electronegativity of X. The cation pools served as versatile reagents for organic synthesis; the reactions with alkenes gave β-X-substituted alkoxysulfonium ions, which were converted to the corresponding carbonyl compounds by the treatment with triethylamine, whereas the treatment with methanol gave the corresponding alcohols. The reactions with aminoalkenes and 1,6-dienes gave the cyclized products.
