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。
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.
irradiation from a compact fluorescent lamp, low-intensity UV lamp, or sunlight. This protocol can be applied to the synthesis of perfluoroalkyl-substituted phenanthridines as well as effect the iodo-perfluoroalkylation of alkenes/alkynes and the C–H perfluoroalkylation of electron-rich arenes and heteroarenes. This C–H perfluoroalkylation reaction offers a unique method for site-selective labeling of oligopeptides
Synthesis of 6-aroyl phenanthridines by Fe-catalyzed oxidative radical cyclization of 2-isocyanobiphenyls with benzylic alcohols
作者:Ziyi Nie、Qiuping Ding、Yiyuan Peng
DOI:10.1016/j.tet.2016.11.010
日期:2016.12
A practical method for the synthesis of 6-aroyl phenanthridine derivatives by Fe-catalyzed oxidative radicalcyclization of 2-isocyanobiphenyls with benzylic alcohols is described. In addition, this cyclization could be occurred by using toluene as aroyl source. The procedure tolerates various functional groups under simple conditions. A single-electron-transfer pathway is proposed according to mechanistic
Selective C(sp<sup>3</sup>)–H activation of simple alkanes: visible light-induced metal-free synthesis of phenanthridines with H<sub>2</sub>O<sub>2</sub> as a sustainable oxidant
A visible light-induced metal-free C(sp3)–H phenanthridinylation of simple alkanes with isonitrile is developed with H2O2 as a terminal sustainable oxidant.