The first example of benzylic C-H triflylation was accomplished with pyridine as a directing group. The reac- tion of various 2-benzylpyridines and （CF3SO2）20 in the presence of NEt3 in CH2Cl2 proceeded smoothly to ...The first example of benzylic C-H triflylation was accomplished with pyridine as a directing group. The reac- tion of various 2-benzylpyridines and （CF3SO2）20 in the presence of NEt3 in CH2Cl2 proceeded smoothly to afford the corresponding benzyl triflones in moderate to high yields.展开更多
A series of novel γ,γ-difluorinated Goniothalamin analogues 4a--4i and 6a--6i were synthesized. The key steps included the construction of C-5 stereocenter adjacent to gem-difluoromethylene group by way of lipase AK...A series of novel γ,γ-difluorinated Goniothalamin analogues 4a--4i and 6a--6i were synthesized. The key steps included the construction of C-5 stereocenter adjacent to gem-difluoromethylene group by way of lipase AK catalyzed kinetic resolution, the introduction of aryl group via Stille coupling, and lactonization by 1,5-oxidative cycli- zation. These γ,γ-difluorinated Goniothalamin analogues 4a-4i and their enanfiomers 6a--6i, together with several corresponding 7-monofluorinated Goniothalamin analogues were biologically evaluated against four different cancer cell lines. Compound 7h showed a nearly equivalent potency as the parent （R）-Goniothalamin in the micromolar range. The different fluorine effects between fluoromethylene and gem-difluoromethylene on antitumor activity were discussed through the analysis of bioassay data.展开更多
An iron-catalyzed coupling reaction of difluoroenol silyl ethers and cyclobutanone oxime esters is described. This protocol provides a convenient access to various previously unknown and potentially useful gem-difluor...An iron-catalyzed coupling reaction of difluoroenol silyl ethers and cyclobutanone oxime esters is described. This protocol provides a convenient access to various previously unknown and potentially useful gem-difluoromethylenated ketonitriles inmoderate to good yields. The transformations of resulting products to other fluorinecontaining products is also documented.展开更多
基金We are grateful for the financial support from National Natural Science Foundation of China （Nos. 21502215, 21421002, 21332010, 21272036）, Strategic Priority Research Program of the Chinese Academy of Sciences （No. XDB20020000）, Youth Innovation Pro- motion Association CAS （No. 2016234）, and Shanghai Puj iang Program （No. 15PJ 1410300）.
文摘The first example of benzylic C-H triflylation was accomplished with pyridine as a directing group. The reac- tion of various 2-benzylpyridines and （CF3SO2）20 in the presence of NEt3 in CH2Cl2 proceeded smoothly to afford the corresponding benzyl triflones in moderate to high yields.
基金National Natural Science Foundation of China，National Basic Research Program of China，Scientific Research Program of Sichuan University of Science & Engineering (Nos.2012RC17,2012RC15) are greatly acknowledged for funding this work
文摘A series of novel γ,γ-difluorinated Goniothalamin analogues 4a--4i and 6a--6i were synthesized. The key steps included the construction of C-5 stereocenter adjacent to gem-difluoromethylene group by way of lipase AK catalyzed kinetic resolution, the introduction of aryl group via Stille coupling, and lactonization by 1,5-oxidative cycli- zation. These γ,γ-difluorinated Goniothalamin analogues 4a-4i and their enanfiomers 6a--6i, together with several corresponding 7-monofluorinated Goniothalamin analogues were biologically evaluated against four different cancer cell lines. Compound 7h showed a nearly equivalent potency as the parent （R）-Goniothalamin in the micromolar range. The different fluorine effects between fluoromethylene and gem-difluoromethylene on antitumor activity were discussed through the analysis of bioassay data.
基金National Natural Science Foundation of China (Nos.21421002,21991211)the Strategic Priority Research Program of the Chinese Academy of Sciences (No.XDB20000000)。
文摘An iron-catalyzed coupling reaction of difluoroenol silyl ethers and cyclobutanone oxime esters is described. This protocol provides a convenient access to various previously unknown and potentially useful gem-difluoromethylenated ketonitriles inmoderate to good yields. The transformations of resulting products to other fluorinecontaining products is also documented.
