Amides as precursors of imidoyl radicals in cyclisation reactions
作者:W. Russell Bowman、Anthony J. Fletcher、Jan M. Pedersen、Peter J. Lovell、Mark R.J. Elsegood、Elena Hernández López、Vickie McKee、Graeme B.S. Potts
DOI:10.1016/j.tet.2006.10.030
日期:2007.1
Amides have been successfully used as precursors of imidoyl radicals for radical cyclisation. The amides have been converted to imidoyl selanides via reaction with phosgene to yield imidoyl chlorides followed by reaction with potassium phenylselanide. Imidoyl selanides were reacted with tributyltin hydride (Bu3SnH) as the radical mediator with triethylborane or AIBN as initiators to yield imidoyl radicals
Palladium‐Catalyzed C−H Alkynylation of Unactivated Alkenes
作者:Benedikt S. Schreib、Marlene Fadel、Erick M. Carreira
DOI:10.1002/anie.202000935
日期:2020.5.11
Palladium-catalyzedregio- and diastereoselective C-H functionalization with bromoalkynes and electronically unbiased olefins is reported. The picolinamide directing group enables the formation of putative 5 and 6-exo-metallacycles as intermediates to afford monoalkynylated products in up to 91 % yield in a stereospecific fashion. The systematic study reveals that substrates with a wide range of substituents
Metal-Free Synthesis of 2-Fluoroalkylated Quinolines Using Polyfluoroalkanoic Acids as Direct Fluorine Sources
作者:Jiang Nan、Yan Hu、Pu Chen、Yangmin Ma
DOI:10.1021/acs.orglett.9b00039
日期:2019.4.5
A novel [5 + 1] cyclization of 2-vinylanilines with polyfluoroalkanoic acids under catalyst- and additive-free conditions was successfully implemented. The approach directly employs very low-cost and readily available polyfluoroalkanoic acids as both C1 synthons and fluoroalkyl building blocks. This method provides concise access to diverse 2-fluoroalkylated (CF3, C2F5, C3F7, CF2H, CF2Cl, and CF2Br)
在无催化剂和无添加剂的条件下,成功地实现了多氟链烷酸对2-乙烯基苯胺的新型[5 +1]环化反应。该方法直接采用成本非常低廉且易于获得的多氟链烷酸作为C1合成子和氟代烷基构件。该方法可以简便地获得高收率的多种2-氟烷基化(CF 3,C 2 F 5,C 3 F 7,CF 2 H,CF 2 Cl和CF 2 Br)喹啉,并具有优异的官能团耐受性,且收率高。克秤。
Metal-Free Synthesis of 2-Substituted Quinolines via High Chemoselective Domino Condensation/Aza-Prins Cyclization/Retro-Aldol between 2-Alkenylanilines with β-Ketoesters
作者:Jiang Nan、Pu Chen、Yuxin Zhang、Yun Yin、Bo Wang、Yangmin Ma
DOI:10.1021/acs.joc.0c02063
日期:2020.11.6
A highly chemoselective domino condensation/aza-Prinscyclization/retro-aldol between 2-alkenylanilines with β-dicarbonyl compounds under metal-free conditions was accomplished, giving a large category of valuable 2-substituted quinolines in good yields with excellent functional group toleration. This newly established process, adopting β-ketoesters as masked C1 synthons via C–C cleavage, could even
Synthesis of 2-Quinolinones via a Hypervalent Iodine(III)-Mediated Intramolecular Decarboxylative Heck-Type Reaction at Room Temperature
作者:Huaqiang Fan、Peng Pan、Yongqiang Zhang、Wei Wang
DOI:10.1021/acs.orglett.8b03503
日期:2018.12.21
decarboxylation mechanism is preliminarily revealed. This protocol features metal-free reaction conditions and operational simplicity, allowing the lactamization of 2-vinylanilinesusing a readily accessible carbonyl source and the synthesis of various 2-quinolinones with excellent chemoselectivity at room temperature.