135969-64-1Relevant articles and documents
Synthesis of enantiomers of indanoxazolidinone based on the lipase-catalyzed resolution of the corresponding N-carbamylamino derivative
Suzuki, Masumi,Nagasawa, Chiaki,Sugai, Takeshi
, p. 4841 - 4848 (2001)
Enantiomerically enriched (4R,5S)- and (4S,5R)-indano[1,2-d]oxazolidinones were enzymatically prepared from (±)-1-amino-2-indanol. Racemic 1-(N′-chloroacetyl-N-carbamylamino)-2-indanol O-chloroacetate was hydrolyzed with immobilized Pseudomonas cepacia lipase in the presence of β-cyclodextrin in acetone-buffer solution, to afford (1S,2R)-1-(N′-chloroacetyl-N-carbamylamino)-2-indanol (90%e.e.) and the unreacted (1R,2S)-substrate (97%e.e.), in nearly quantitative yields. The deprotection provided enantiomers of 1-N-carbamylamino-2-indanol, the precursor of indanoxazolidinone, via nitrosation-deaminocyclization reaction.
Catalytic enantioselective synthesis of β-amino alcohols by nitrene insertion
Zhou, Zijun,Tan, Yuqi,Shen, Xiang,Ivlev, Sergei,Meggers, Eric
, p. 452 - 458 (2020/12/31)
Chiral β-amino alcohols are important building blocks for the synthesis of drugs, natural products, chiral auxiliaries, chiral ligands and chiral organocatalysts. The catalytic asymmetric β-amination of alcohols offers a direct strategy to access this class of molecules. Herein, we report a general intramolecular C(sp3)-H nitrene insertion method for the synthesis of chiral oxazolidin-2-ones as precursors of chiral β-amino alcohols. Specifically, the ring-closing C(sp3)-H amination of N-benzoyloxycarbamates with 2 mol% of a chiral ruthenium catalyst provides cyclic carbamates in up to 99% yield and with up to 99% ee. The method is applicable to benzylic, allylic, and propargylic C-H bonds and can even be applied to completely non-activated C (sp3)-H bonds, although with somewhat reduced yields and stereoselectivities. The obtained cyclic carbamates can subsequently be hydrolyzed to obtain chiral β-amino alcohols. The method is very practical as the catalyst can be easily synthesized on a gram scale and can be recycled after the reaction for further use. The synthetic value of the new method is demonstrated with the asymmetric synthesis of a chiral oxazolidin-2-one as intermediate for the synthesis of the natural product aurantioclavine and chiral β-amino alcohols that are intermediates for the synthesis of chiral amino acids, indane-derived chiral Box-ligands, and the natural products dihydrohamacanthin A and dragmacidin A.[Figure not available: see fulltext.].
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 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.
Catalytic, enantioselective N-acylation of lactams and thiolactams using amidine-based catalysts
Yang, Xing,Bumbu, Valentina D.,Liu, Peng,Li, Ximin,Jiang, Hui,Uffman, Eric W.,Guo, Lei,Zhang, Wei,Jiang, Xuntian,Houk,Birman, Vladimir B.
supporting information, p. 17605 - 17612 (2013/01/15)
In contrast to alcohols and amines, racemic lactams and thiolactams cannot be resolved directly via enzymatic acylation or classical resolution. Asymmetric N-acylation promoted by amidine-based catalysts, particularly Cl-PIQ 2 and BTM 3, provides a convenient method for the kinetic resolution of these valuable compounds and often achieves excellent levels of enantioselectivity in this process. Density functional theory calculations indicate that the reaction occurs via N-acylation of the lactim tautomer and that cation-π interactions play a key role in the chiral recognition of lactam substrates.
Copper-catalyzed intramolecular C-H amination
Barman, Dipti N.,Nicholas, Kenneth M.
supporting information; experimental part, 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.
Synthesis of α-CF3-substituted carbonyl compounds with relative and absolute stereocontrol using electrophilic CF3-transfer reagents
Matousek, Vaclav,Togni, Antonio,Bizet, Vincent,Cahard, Dominique
supporting information; experimental part, p. 5762 - 5765 (2012/01/06)
Evans-type chiral lithium imide enolates undergo diastereoselective α-trifluoromethylation with a hypervalent iodine-CF3 reagent with up to 91% combined isolated yield and 97:3 dr. The resulting isolated diastereopure products can be further transformed into valuable products without racemization.
Catalysts for use in enantioselective synthesis
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Page/Page column 60; 65-66, (2008/12/05)
Disclosed are compounds having the following formula: in which Z11 is selected from a substituted or unsubstituted saturated adamantyl or other polycyclic group and a substituted or unsubstituted branched acyclic group containing at least 5 carbon atoms at least one of which is a tertiary carbon; and in which Z12 is a cyclic imide. Methods of using these compounds as chiral catalysts for carbenoid reactions and for enantioselective C—H aminations are also described.
A silver-catalyzed intramolecular amidation of saturated C-H bonds
Cui, Yong,He, Chuan
, p. 4210 - 4212 (2007/10/03)
Opportunities with silver: A dinuclear silver(I) compound was found to efficiently catalyze the intramolecular amidation of saturated C-H bonds of carbamates and sulfamates (see scheme). This highly regioselective, stereospecific reaction offers a practical method for the construction of cyclic nitrogen-containing organic molecules.
