functionalized N-amino-3-nitrile-indole derivatives are obtained via an intramolecular hetero-cyclization of 2-aryl-3-substituted hydrazono-alkylnitriles using FeBr3 as a single electron oxidant. This approach allows the N-moiety on the side-chain to be annulated to the benzene ring during the final synthetic step via direct oxidative aromatic C–N bond formation.
A catalytic enantioselective synthetic strategy for the aryl-substituted all-carbon quaternary stereocenters of bioactive hydrodibenzofuran alkaloids was achieved by the Michael addition reaction of α-cyano ketones and acrylates using a chiral tertiary amine–thiourea catalyst. This method can tolerate steric bulkiness and multiple functional groups, and 32 Michael adducts were prepared in good to excellent
intramolecular cyclization of electron-rich α-aryl ketones. The alkoxy substituent on the benzene ring in the substrates was essential for an efficient cyclization to occur. This novel method allows the construction of benzo[b]furan rings by joining the O-atom on the side chain to the benzene ring via direct oxidative aromatic C−O bond formation.
通过FeCl 3介导的富电子α-芳基酮的分子内环化,获得了多种3-官能化的苯并[ b ]呋喃。底物中苯环上的烷氧基取代基对于有效环化的发生至关重要。这种新方法允许通过直接氧化芳香族C-O键形成将侧链上的O原子与苯环相连,从而构造苯并[ b ]呋喃环。
Iodobenzene Dichloride/Zinc Chloride-Mediated Synthesis of <i>N</i>
-Alkoxyindole-3-carbonitriles from 3-Alkoxyimino-2-arylalkylnitriles via Intramolecular Heterocyclization
作者:Zhongxiang Yun、Ran Cheng、Jiyun Sun、Daisy Zhang-Negrerie、Yunfei Du
DOI:10.1002/adsc.201701111
日期:2018.1.17
heterocyclization of the readily available 3‐alkoxyimino‐2‐arylalkylnitriles mediated by iodobenzene dichloride/zinc chloride. The mechanism of the reaction proposes the formation of a key intermediate of nitrenium cation from a chlorination and dechlorination process facilitated by the hypervalent iodine reagent and Lewis acid respectively.
Synthesis of N-Substituted Indole Derivatives via PIFA-Mediated Intramolecular Cyclization
作者:Yunfei Du、Renhe Liu、Gregory Linn、Kang Zhao
DOI:10.1021/ol062288o
日期:2006.12.1
A variety of N- arylated and N- alkylated indole derivatives were synthesized by way of a phenyliodine bis( trifluoroacetate) ( PIFA)- mediated intramolecular cyclization. This novel method allows for the construction of an indole skeleton by joining the N- atom on the side chain to the benzene ring at the last synthetic step. Other novel pyrrole- fused aromatic compounds can also be achieved by this method.