Transition-Metal-Free Synthesis of C-Glycosylated Phenanthridines via K<sub>2</sub>S<sub>2</sub>O<sub>8</sub>-Mediated Oxidative Radical Decarboxylation of Uronic Acids
作者:Xin Zhou、Peng Wang、Li Zhang、Pengwei Chen、Mingxu Ma、Ni Song、Sumei Ren、Ming Li
DOI:10.1021/acs.joc.7b02346
日期:2018.1.19
efficient protocol for the synthesis of C-glycosylated phenanthridines. Tetrafuranos-4-yl and pentapyranos-5-yl radicals, generated from K2S2O8-mediated oxidative decarboxylation of furan- and pyranuronic acids, undergo attack to 2-isocyanodiphenyls and ensuing homolytic aromatic substitution to provide diverse C-glycosylated phenanthridines in satisfactory yields without resort to transition metals.
我们已经开发出一种用于合成C-糖基化菲啶的有效方案。由K 2 S 2 O 8介导的呋喃酸和吡喃糖醛酸的氧化脱羧反应生成的四氢呋喃-4-基和五吡喃基-5-基遭受2-异氰基二苯基的攻击,随后发生均相芳族取代,从而提供多种C-糖基化的菲啶无需过渡金属即可获得令人满意的收率。该反应可耐受各种官能团,并能方便地合成复杂的基于寡糖的菲啶。已经制备了衍生自β-环糊精的C-糖基化菲啶,由于其灵活的构象,在医学和生物化学中可能具有潜力。
Silver‐Enabled General Radical Difluoromethylation Reaction with TMSCF
<sub>2</sub>
H
A silver‐mediated oxidative difluoromethylation of styrenes and vinyl trifluoroborates with TMSCF2H is reported for the first time. This method enables direct and facile access to CF2H‐alkenes from abundant alkenes with excellent functional‐group compatibility. Moreover, this Ag/TMSCF2H protocol could further enable a series of radical difluoromethylation reactions of a wide array of substrates, offering
Free-Radical Triggered Ordered Domino Reaction: An Approach to C–C Bond Formation via Selective Functionalization of α-Hydroxyl-(sp<sup>3</sup>)C–H in Fluorinated Alcohols
作者:Zhengbao Xu、Zhaojia Hang、Zhong-Quan Liu
DOI:10.1021/acs.orglett.6b01946
日期:2016.9.16
free-radical mediated highly ordered radical addition/cyclization/(sp3)C–C(sp3) formation domino reaction is developed. Three new C–C bonds are formed one by one in a mixed system. Furthermore, it represents the first example of cascade C–C bond formation via selective functionalization of α-hydroxyl-C(sp3)–H in fluorinated alcohols.
Convenient synthesis of 6-alkyl phenanthridines and 1-alkyl isoquinolines via silver-catalyzed oxidative radical decarboxylation
作者:Qian Yao、Xin Zhou、Xiuli Zhang、Cong Wang、Peng Wang、Ming Li
DOI:10.1039/c6ob02331b
日期:——
convenient and efficient protocol for the synthesis of 6-alkyl phenanthridines and 1-alkyl isoquinolines has been developed. The reaction relies on the coupling of 2-isocyanobiphenyls and vinyl isonitriles with alkyl radicals formed by the silver-catalyzed decarboxylation of stoichiometric aliphatic carboxylic acids, and affords diverse phenanthridine and isoquinoline derivatives under mild reaction conditions
Ni-catalyzed reductive addition of alkyl halides to isocyanides
作者:Bo Wang、Yijing Dai、Weiqi Tong、Hegui Gong
DOI:10.1039/c5ob01901j
日期:——
Ni-catalyzed reductive trapping of secondary and tertiary alkyl radicals with both electron-rich and electron-deficient aryl isocyanides using zinc as the terminal reductant, affording 6-alkylated phenanthridine in good yields. The employment of carbene ligands necessitates the alkyl radical process, and represents the first utility in the Ni-catalyzed reductive conditions for the generation of unactivated