69776-88-1Relevant academic research and scientific papers
Tuning Triplet Energy Transfer of Hydroxamates as the Nitrene Precursor for Intramolecular C(sp3)-H Amidation
Chang, Sukbok,Jung, Hoimin,Keum, Hyeyun,Kweon, Jeonguk
, p. 5811 - 5818 (2020/04/10)
Reported herein is the design of a photosensitization strategy to generate triplet nitrenes and its applicability for the intramolecular C-H amidation reactions. Substrate optimization by tuning physical organic parameters according to the proposed energy transfer pathway led us to identify hydroxamates as a convenient nitrene precursor. While more classical nitrene sources, representatively organic azides, were ineffective under the current photosensitization conditions, hydroxamates, which are readily available from alcohols or carboxylic acids, are highly efficient in accessing synthetically valuable 2-oxazolidinones and γ-lactams by visible light. Mechanism studies supported our working hypothesis that the energy transfer path is mainly operative.
Versatile Cp*Co(III)(LX) Catalyst System for Selective Intramolecular C-H Amidation Reactions
Chang, Sukbok,Jung, Hoimin,Kim, Dongwook,Lee, Jeonghyo,Lee, Jia,Park, Juhyeon
, p. 12324 - 12332 (2020/08/06)
Herein, we report the development of a tailored cobalt catalyst system of Cp*Co(III)(LX) toward intramolecular C-H nitrene insertion of azidoformates to afford cyclic carbamates. The cobalt complexes were easy to prepare and bench-stable, thus offering a convenient reaction protocol. The catalytic reactivity was significantly improved by the electronic tuning of the bidentate LX ligands, and the observed regioselectivity was rationalized by the conformational analysis and DFT calculations of the transition states. The superior performance of the newly developed cobalt catalyst system could be broadly applied to both C(sp2)-H and C(sp3)-H carbamation reactions under mild conditions.
Synthesis of Chiral 5-Aryl-2-oxazolidinones via Halohydrin Dehalogenase-Catalyzed Enantio- and Regioselective Ring-Opening of Styrene Oxides
Wan, Nanwei,Zhou, Xiaoying,Ma, Ran,Tian, Jiawei,Wang, Huihui,Cui, Baodong,Han, Wenyong,Chen, Yongzheng
supporting information, p. 1201 - 1207 (2020/02/05)
An efficient biocatalytic approach for enantio- and regioselective ring-opening of styrene oxides with cyanate was developed by using the halohydrin dehalogenase HheC from Agrobacterium radiobacter AD1, generating the corresponding chiral 5-aryl-2-oxazoli
Method of biocatalytically synthesizing 4-substituted oxazolidinone compound
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Paragraph 0047; 0048; 0049, (2019/04/27)
The invention discloses a biocatalytic technology of synthesizing a 4-substituted oxazolidinone compound by carrying out a reaction on a halohydrin dehalogenase catalyzed epoxy compound and cyanate. The reaction takes the epoxy compound as a primer, cyanate as a nucleophilic ring opening reagent and halohydrin dehalogenase which is originated from an Ilumatobacter coccineus strain and has high alpha-offensive ring opening area selectivity as a biocatalyst. The reaction is carried out in a water phase and is mild in reaction condition. The invention is the biocatalytic method of catalyzing theepoxy compound to synthesize the 4-substituted oxazolidinone compound by using the halohydrin dehalogenase for the first time. The method has a wide application prospect in design of an oxazolidinonedrug and green manufacturing aspect thereof.
Synthesis of oxazolidinones: Rhodium-catalyzed C-H amination of: N -mesyloxycarbamates
Lebel, Hélène,Mamani Laparra, Laura,Khalifa, Maroua,Trudel, Carl,Audubert, Clément,Szponarski, Mathieu,Dicaire Leduc, Cédric,Azek, Emna,Ernzerhof, Matthias
, p. 4144 - 4158 (2017/07/10)
N-Mesyloxycarbamates undergo intramolecular C-H amination reactions to afford oxazolidinones in good to excellent yields in the presence of rhodium(ii) carboxylate catalysts. The reaction is performed under green conditions and potassium carbonate is used, forming biodegradable potassium mesylate as a reaction by-product. This method enables the production of electron-rich, electron-deficient, aromatic and heteroaromatic oxazolidinones in good to excellent yields. Conformationally restricted cyclic secondary N-mesyloxycarbamates furnish cis-oxazolidinones in high yields and selectivity; DFT calculations are provided to account for the observed selectivity. trans-Oxazolidinones were prepared from acyclic secondary N-mesyloxycarbamates using Rh2(oct)4. The selectivity was reverted with a cytoxazone N-mesyloxycarbamate precursor using large chiral rhodium(ii) carboxylate complexes, affording the corresponding cis-oxazolidinone. This orthogonal selectivity was used to achieve the formal synthesis of (-)-cytoxazone.
(Enantio)selective Hydrogen Autotransfer: Ruthenium-Catalyzed Synthesis of Oxazolidin-2-ones from Urea and Diols
Pe?a-López, Miguel,Neumann, Helfried,Beller, Matthias
supporting information, p. 7826 - 7830 (2016/07/07)
A novel strategy for the synthesis of oxazolidin-2-ones from vicinal diols and urea is described. In this heterocycle synthesis, two different C?O and C?N bonds are sequentially formed in a domino process consisting of nucleophilic substitution and alcohol amination. The use of readily available starting materials and the good atom economy render this process environmentally benign. While this transformation is already highly chemo- and regioselective, we also developed the first asymmetric version of this method using (R)-(+)-MeO-BIPHEP as the chiral ligand.
Copper-catalyzed intramolecular C-H amination
Barman, Dipti N.,Nicholas, Kenneth M.
, p. 908 - 911 (2011/04/26)
The amino-functionalization of tertiary, secondary and benzylic C-H bonds of tethered carbamates and sulfamates by iodosobenzene is catalyzed by Cu I-diimine complexes in moderate to good yield. Employing homochiral imine-Cucatalysts affords oxazolidinones and oxathiazinanes with modest enantioselectivity.
THE INTRAMOLECULAR CHEMISTRY OF BENZYL AND PHENETHYL AZIDOFORMATES
Meth-Cohn, Otto,Patel, Dalpat,Rhouati, Salah
, p. 5085 - 5088 (2007/10/02)
Benzyl azidoformates yield one of a variety of products on spray pyrolysis dependent upon substitution, including oxazoloazepines, their syn or anti dimers, their dimers, a benzoxazinone or aryl isocyanate; the phenethyl analogues give stable oxazinoazepines.
