Ag_(2)CO_(3)-promoted dehydroxymethylative fluorination of aliphatic alcohols has been achieved with Selectfluor as both oxidant and fluorine source.The reaction involvesβ-fragmentation of primary alkoxy radicals,fol...Ag_(2)CO_(3)-promoted dehydroxymethylative fluorination of aliphatic alcohols has been achieved with Selectfluor as both oxidant and fluorine source.The reaction involvesβ-fragmentation of primary alkoxy radicals,followed by the fluorination of the resulting C-centered radical intermediates.The transformation proceeds under mild reaction conditions and exhibits a broad substrate scope,thus opening up a new entrance to the synthesis of fluorinated constructs includingα-fluoroimides and 1-fluoroalkyl benzoates as well as secondary and tertiary alkyl fluorides like versatile 2-fluoro-2-alkyl 1,3-propandiol derivatives.The divergent functionalization of the obtainedα-fluoroimides enables an efficient access to amine derivatives through C-F bond activation under the action of BF_(3)·OEt_(2).展开更多
The first assembly of a conjugation-ready hexasaccharide from the capsular glycan of C.jejuni.strain BH0142 has been accomplished.The synthesis features the efficient preparation of 6-deoxy-D-idoheptopyranosyl fluorid...The first assembly of a conjugation-ready hexasaccharide from the capsular glycan of C.jejuni.strain BH0142 has been accomplished.The synthesis features the efficient preparation of 6-deoxy-D-idoheptopyranosyl fluoride donors proceeding from allylα-D-C-glucopyranoside by a C1-to-C5 switch strategy with radical dehydroxymethylative fluorination as a key step,stereocontrolled construction of 1,2-trans-α-D-ido-heptopyranosidic bonds and of 1,2-cis-α-D-galactopyranosidic linkages.The obtained target oligosaccharide sets a solid foundation for making structurally-defined multivalent glycoconjugate vaccine candidates against C.jejuni.infections.展开更多
基金financial support from the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2022QNLM030003-2)the National Natural Science Foundation of China(No.21977088)the National Natural Science Foundation of China-Shandong Joint Fund(No.U1906213)。
文摘Ag_(2)CO_(3)-promoted dehydroxymethylative fluorination of aliphatic alcohols has been achieved with Selectfluor as both oxidant and fluorine source.The reaction involvesβ-fragmentation of primary alkoxy radicals,followed by the fluorination of the resulting C-centered radical intermediates.The transformation proceeds under mild reaction conditions and exhibits a broad substrate scope,thus opening up a new entrance to the synthesis of fluorinated constructs includingα-fluoroimides and 1-fluoroalkyl benzoates as well as secondary and tertiary alkyl fluorides like versatile 2-fluoro-2-alkyl 1,3-propandiol derivatives.The divergent functionalization of the obtainedα-fluoroimides enables an efficient access to amine derivatives through C-F bond activation under the action of BF_(3)·OEt_(2).
基金financial support from the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2022QNLM030003-2)the National Natural Science Foundation of China(Nos.21977088 and 21672194)the National Natural Science Foundation of China-Shandong Joint Foundation(No.U1906213)。
文摘The first assembly of a conjugation-ready hexasaccharide from the capsular glycan of C.jejuni.strain BH0142 has been accomplished.The synthesis features the efficient preparation of 6-deoxy-D-idoheptopyranosyl fluoride donors proceeding from allylα-D-C-glucopyranoside by a C1-to-C5 switch strategy with radical dehydroxymethylative fluorination as a key step,stereocontrolled construction of 1,2-trans-α-D-ido-heptopyranosidic bonds and of 1,2-cis-α-D-galactopyranosidic linkages.The obtained target oligosaccharide sets a solid foundation for making structurally-defined multivalent glycoconjugate vaccine candidates against C.jejuni.infections.
