copper(II) salts and Dess–Martin periodinane via radical intermediates, as evidenced by TEMPO spin‐trapping experiments. This new method of radical generation is compatible with functionalization and CC bond formation through Giese‐type addition reactions (see scheme; DMSO=dimethyl sulfoxide, TEMPO=2,2,6,6‐tetramethyl‐1‐piperidinyloxyl, free radical).
Continuous UV-Flow Microsystem for Efficient Radical Generation from Organotrifluoroborates by Photoredox Catalysis
作者:Nassim El Achi、Maël Penhoat、Youssef Bakkour、Christian Rolando、Laëtitia Chausset-Boissarie
DOI:10.1002/ejoc.201600728
日期:2016.9
An efficient continuous-flow protocol for C–O and C–C bond formation fromorganoborates by photoredoxcatalysis under UV irradiation was explored. The combination of a cyclometalated iridium photocatalyst, high-power UV light-emitting diode irradiation, and microreactor technology resulted in very efficient radicalgeneration. The flow device enabled determination of highly accurate kinetic data that
Reactions of allyloxy(methoxy)carbene in solution. Carbene rearrangement and Claisen rearrangement of the carbene dimer
作者:Damian Plazuk、John Warkentin、Nick Henry Werstiuk
DOI:10.1016/j.tet.2005.04.024
日期:2005.6
Allyloxy(methoxy)carbene, with and without deuterium in the α-position of the allyloxy group, was generated in benzene at 50 and at 110 °C. At the higher temperature, the carbene fragmented to allyl and methoxycarbonyl radicals that subsequently coupled. At the lower temperature, most of the carbene dimerised. The structure of the major product and the distribution of deuterium indicated that the dimer
Selective Defluoroallylation of Trifluoromethylarenes
作者:Chaosheng Luo、Jeffrey S. Bandar
DOI:10.1021/jacs.9b07766
日期:2019.9.11
report a fluoride-initiated coupling reaction between trifluoromethylarenes and allylsilanes to access allylated α,α-difluorobenzylic compounds. This method's utility is demonstrated through a 30 mmol scale reaction, a sequential allylation/derivatization protocol and multiple examples of site-selective trifluoromethylarene allylation. Initial mechanistic studies suggest a base-induced single electron
In this report, the single-electron-transfer oxidation of alkyltrifluoroborates and silicates has been studied. Different types of oxidation reagents have been examined, focusing on organic oxidants and particularly the use of dyes in photocatalytic oxidations. Both trifluoroborates and silicates could provide C-centered radicals when using a tritylium salt or the Ledwith–Weitz aminium salt. Photocatalysis
在本报告中,研究了烷基三氟硼酸盐和硅酸盐的单电子转移氧化。已经研究了不同类型的氧化试剂,重点是有机氧化剂,特别是染料在光催化氧化中的使用。当使用三苯甲基盐或 Ledwith-Weitz 铵盐时,三氟硼酸盐和硅酸盐都可以提供 C 中心自由基。Fukuzumi 试剂的光催化表明,在这些条件下,三氟硼酸盐比双儿茶酚硅酸盐更容易氧化。