- Catalytic Access to Functionalized Allylic gem-Difluorides via Fluorinative Meyer–Schuster-Like Rearrangement
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An unprecedented approach for efficient synthesis of functionalized allylic gem-difluorides via catalytic fluorinative Meyer–Schuster-like rearrangement is disclosed. This transformation proceeded with readily accessible propargylic fluorides, and low-cost B–F reagents and electrophilic reagents by sulfide catalysis. A series of iodinated, brominated, and trifluoromethylthiolated allylic gem-difluorides that were difficult to access by other methods were facilely produced with a wide range of functional groups. Importantly, the obtained iodinated products could be incorporated into different drugs and natural products, and could be expediently converted into many other valuable gem-difluoroalkyl molecules as well. Mechanistic studies revealed that this reaction went through a regioselective fluorination of alkynes followed by a formal 1,3-fluorine migration under the assistance of the B–F reagents to give the desired products.
- An, Rui,Li, Huimin,Liao, Lihao,Wu, Jin-Ji,Xu, Yang,Zhao, Xiaodan
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p. 11010 - 11019
(2020/05/18)
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- Preparation method of medicine ezetimibe for treating hyperlipidemia
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The invention discloses a preparation method of a medicine ezetimibe for treating hyperlipidemia, belonging to the field of pharmaceutical synthesis. According to the preparation method, a compound 2is taken as a raw material, and the ezetimibe 1 is prepared by four steps of carbonyl protection, cyclization, carbonyl reduction and oxidation. Compared with the existing method reported by documents, the preparation method provided by the invention avoids the use of a polluting titanium reagent, and is fewer in synthesis steps, higher in process stability and suitable for large-scale production.
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Paragraph 0026; 0033; 0040
(2018/03/26)
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- SYNTHESIS OF EZETIMIBE
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The present disclosure relates to processes for the preparation of Ezetimibe (1-(4-fluorophenyl)-3(R)-[3-(4-fluorophenyl)-3(S)-hydroxypropyl]-4(S)-(4-hydroxyphenyl)-2-azetidinone) and related azetidine compounds.
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Page/Page column 57
(2010/12/29)
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