Oxindole synthesis by palladium-catalysed aromatic C–H alkenylation
作者:Satoshi Ueda、Takahiro Okada、Hideko Nagasawa
DOI:10.1039/b926560k
日期:——
A strategy involving palladium-catalysed aromatic C-H functionalisation/intramolecular alkenylation provides a convenient and direct synthesis of 3-alkylideneoxindoles. In the presence of 5 mol% of PdCl(2)MeCN(2) and AgOCOCF(3), a wide variety of N-cinnamoylanilines gave 3-alkylideneoxindoles in moderate to good yield.
FeCl<sub>2</sub>-Catalyzed Decarboxylative Radical Alkylation/Cyclization of Cinnamamides: Access to Dihydroquinolinone and Pyrrolo[1,2-<i>a</i>]indole Analogues
作者:Zhihao Cui、Da-Ming Du
DOI:10.1021/acs.joc.8b00511
日期:2018.5.4
91%) with excellent diastereoselectivity (>20:1 dr) was developed. The inexpensive FeCl2·4H2O works as catalyst, and easily prepared peresters (or peroxides) from aliphatic acids act as alkylating reagents and single electron oxidants. This environmentally friendly reaction proceeds via an FeCl2-catalyzed alkyl radical cascade addition/cyclization fashion.
开发了一种简单且统一的方法,以中等至高收率(高达91%)合成具有非对映选择性(> 20:1 dr)的烷基化二氢喹啉酮和吡咯并[1,2- a ]吲哚衍生物。廉价的FeCl 2 ·4H 2 O用作催化剂,由脂肪酸容易制得的过酸酯(或过氧化物)用作烷基化试剂和单电子氧化剂。该环境友好的反应通过FeCl 2催化的烷基自由基级联加成/环化方式进行。
Catalyst-Free, Direct Electrochemical Tri- and Difluoroalkylation/Cyclization: Access to Functionalized Oxindoles and Quinolinones
The catalyst-free electrochemical di- and trifluoromethylation/cyclization of N-substituted acrylamides was realized under external oxidant-free conditions. The strategy provides expedient access to fluoroalkylated oxindoles and 3,4-dihydroquinolin-2(1H)-ones with ample scope and broad functional group tolerance by mild, direct electrolysis of sodium sulfinates in an undivided cell. Detailed mechanistic
friendly, and efficient electrochemical selenylation/cyclization of alkenes has been developed with moderate to excellent yields. This selenylated transformation proceeds smoothly and tolerates a wide range of synthetically useful groups to deliver diverse functionalized benzheterocycles, including iminoisobenzofuran, lactones, oxindoles, and quinolinones. Moreover, the present syntheticroute could also
An efficient, silver-induced tandem radical addition/cyclization for the synthesis of 3,4-dihydroquinolinones is presented, which exhibits a good functional group tolerance. The reaction is easy to operate and amenable to a multigram-scale synthesis. Additionally, this work illustrates the formation of a key skeleton for the synthesis of biologically interesting 3,4-dihydroquinolinone alkaloids.