28291-10-3Relevant academic research and scientific papers
Synthesis of Epoxides from Alkyl Bromides and Alcohols with in Situ Generation of Dimethyl Sulfonium Ylide in DMSO Oxidations
Zhang, Zhi-Wei,Li, Hai-Bo,Li, Jin,Wang, Cui-Cui,Feng, Juan,Yang, Yi-Hua,Liu, Shouxin
, p. 537 - 547 (2020/01/02)
Direct conversion of the readily available alkyl bromides and alcohols to value-added epoxides using dimethyl sulfoxide (DMSO) under mild reaction conditions has been developed. Benzyl and allyl bromides, and activated and unactivated alcohols all proceeded smoothly to give epoxides in high to excellent yield. Dimethyl sulfide, generated by DMSO oxidations, was in situ elaborated to form the substituted dimethyl sulfonium ylide species that participates in the Corey-Chaykovsky epoxidation in a domino and one-pot fashion, respectively.
Method used for direct synthesis of epoxy compounds from alcohol
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Paragraph 0140-0147, (2019/10/08)
The invention discloses a method used for direct synthesis of an epoxy compounds from an alcohol. According to the method, an alcohol is taken as a raw material, Swern oxidation is adopted to synthesize an aldehyde, a bromo-hydrocarbon and an alkali are added into the aldehyde directly to construct epoxy functional groups, and generate the epoxy compound. According to the method, one-pot method is adopted to realize direct epoxidation of the alcohol, the synthesis route is simple, the preparation process is easy to control, no catalyst is needed in the process, substrate suitable range is wide, reagents are cheap and easily available, preparation conditions are mild, reaction yield is high, and the method is suitable for synthesis of epoxy compounds.
The B(C6F5)3-Catalyzed Tandem Meinwald Rearrangement-Reductive Amination
Tiddens, Martine R.,Klein Gebbink, Robertus J. M.,Otte, Matthias
supporting information, p. 3714 - 3717 (2016/08/16)
A system of three coupled catalytic cycles enabling the one-pot transformation of epoxides to amines via Meinwald rearrangement, imine condensation, and imine reduction is described. This assisted tandem catalysis is catalyzed by B(C6F5)3 resulting in the first tandem Meinwald rearrangement-reductive amination protocol. The reaction proceeds in nondried solvents and yields β-functionalized amines. In particular, β-diarylamines are obtained in high yields.
Benzylic Ammonium Ylide Mediated Epoxidations
Roiser, Lukas,Robiette, Rapha?l,Waser, Mario
, p. 1963 - 1968 (2016/08/10)
A high yielding synthesis of stilbene oxides using ammonium ylides has been developed. It turned out that the amine leaving group plays a crucial role as trimethylamine gives higher yields than DABCO or quinuclidine. The amine group also influences the diastereoselectivity, and detailed DFT calculations to understand the key parameters of these reactions have been carried out.
A non-heme iron(III) complex with porphyrin-like properties that catalyzes asymmetric epoxidation
Niwa, Takashi,Nakada, Masahisa
, p. 13538 - 13541 (2012/10/08)
In this report, we describe an iron(III) complex containing a carbazole-based tridentate ligand that catalyzes highly enantioselective asymmetric epoxidation of (E)-alkenes at room temperature. The non-heme iron(III) complex has a five-coordinated trigonal-bipyramidal structure, and its two-electron oxidized state has the similar electronic structure as that of iron porphyrins.
A new synthesis of trans-2,3-diaryloxiranes and 2-(1 H -benzo[ d ][1,2,3]-triazol-1-yl)-1-arylethanols via the reactions of 1-benzyl-3- methylbenzo-triazolium ylide with aryl aldehydes
Xiao, Xiaohui,Lin, Daqin,Tong, Shuitian,Mo, Hailan
experimental part, p. 2823 - 2826 (2011/12/21)
1-Benzyl-3-methylbenzotriazolium ylide was formed by the reaction of 1-benzyl-3-methylbenzotriazolium iodide with t-BuOK. Subsequently it reacted with various aryl aldehydes to give the corresponding trans-2,3-diaryloxiranes and 2-(1H-benzo-[d][1,2,3]triazol-1-yl)-1-arylethanols in moderate to high yields. Georg Thieme Verlag Stuttgart · New York.
Delineation of the factors governing reactivity and selectivity in epoxide formation from ammonium ylides and aldehydes
Robiette, Raphael,Conza, Matteo,Aggarwal, Varinder K.
, p. 621 - 623 (2007/10/03)
Diastereoselectivity in reactions of aryl-stabilised ammonium ylides are highly sensitive to the nature of the amine and the ylide substituent. DFT calculations are consistent with a mechanism in which reversibility in betaine formation [despite the high energy (and therefore instability) of ammonium ylides] is finely balanced due to the high barrier to ring closure. The Royal Society of Chemistry.
New camphor-derived selenonium ylides: Enantioselective synthesis of chiral epoxides
Li, Xin-Liang,Wang, Yi,Huang, Zhi-Zhen
, p. 749 - 752 (2007/10/03)
Optically pure selenonium salts 3 as the precursors of two new chiral selenonium ylides 4 can be synthesized stereoselectively from natural d-camphor in good yields. It is found that the reaction of the selenonium salt 3b, an aldehyde, and potassium tert-butoxide can take place smoothly in ?one-pot' via the formation of selenonium ylide 4b, to give chiral trans-diaryl epoxides 5 in good yields with good diastereoselectivities and enantioselectivities. CSIRO 2005.
A novel and highly efficient asymmetric synthesis of epoxides via chiral telluronium ylides
Ou, Wen-Hua,Huang, Zhi-Zhen
, p. 2857 - 2860 (2007/10/03)
The one-pot reaction of telluronium salt 8, aldehyde, and potassium tert-butoxide proceeded smoothly via chiral benzyl telluronium ylide, producing trans-(2S,3S)-diaryl epoxides with good yields as well as excellent diastereoselectivities and enantioselectivities (up to 99% ee). Georg Thieme Verlag Stuttgart.
Design of sulfides with a locked conformation as promoters of catalytic and asymmetric sulfonium ylide epoxidation
Davoust, Marion,Briere, Jean-Francois,Jaffres, Paul-Alain,Metzner, Patrick
, p. 4166 - 4169 (2007/10/03)
A new generation of 2,5-dimethylthiolanes with a locked conformation was developed to promote the asymmetric addition of chiral sulfonium ylides to aldehydes. The novel chiral sulfur derivative 4 succeeded the synthesis of trans-stilbene oxide derivatives with enantiomeric ratios ranging from 95:5 to 98:2. This user-friendly organocatalytic process proved to be efficient with 20-10% of sulfide 4 in 1 or 2 days of reaction. An insight into the ylide intermediate conformation is given on the basis of a computational ab initio study.
