A Highly Para-Selective Copper(II)-Catalyzed Direct Arylation of Aniline and Phenol Derivatives
作者:Claire-Lise Ciana、Robert J. Phipps、Jochen R. Brandt、Falco-Magnus Meyer、Matthew J. Gaunt
DOI:10.1002/anie.201004703
日期:2011.1.10
In short order: A copper‐catalyzed Friedel–Crafts‐type strategy has been developed for the title reaction. An iterative CH arylation strategy has also been demonstrated for the functionalization of anilines by sequentially delivering different aromatic groups to the para, ortho, and meta positions (see scheme, Bn=benzyl, Piv=pivaloyl).
Silver-Catalyzed Alkyne Activation: The Surprising Ligand Effect
作者:Yijin Su、Mei Lu、Boliang Dong、Hao Chen、Xiaodong Shi
DOI:10.1002/adsc.201300785
日期:2014.3.10
An unexpected ligand effect was discovered in the silver(I)‐catalyzed alkyneactivation. For both aldehyde‐alkyne‐amine (A3) condensation and intermolecular alkynehydroamination, the type B complex (P:Ag=1:1) effectively promoted the reaction, while no reaction occurred with either no ligand or excess ligands under the identical conditions.
Brønsted Acid Catalyzed Monoalkylation of Anilines with Trichloroacetimidates
作者:Daniel R. Wallach、Patrick C. Stege、Jigisha P. Shah、John D. Chisholm
DOI:10.1021/jo5027222
日期:2015.2.6
under these conditions. Electron-poor anilines provide superior yields, with electron-rich anilines sometimes showing competitive Friedel–Craftsalkylation. A single flask protocol with formation of the imidate in situ is demonstrated, providing a convenient method for the direct substitution of alcohols with anilines. Reaction with a chiral imidate favors a mechanism that proceeds through a carbocation
Remote Construction of N‐Heterocycles via 1,4‐Palladium Shift‐Mediated Double C−H Activation
作者:Takeru Miyakoshi、Nadja E. Niggli、Olivier Baudoin
DOI:10.1002/anie.202116101
日期:2022.4.19
AbstractIn the past years, Pd0‐catalyzed C(sp3)−H activation provided efficient and step‐economical methods to synthesize carbo‐ and heterocycles via direct C(sp2)−C(sp3) bond formation. We report herein that a 1,4‐Pd shift allows access to N‐heterocycles which are difficult to build via a direct reaction. It is shown thato‐bromo‐N‐methylanilines undergo a 1,4‐Pd shift at theN‐methyl group, followed by intramolecular trapping by C(sp2)−H or C(sp3)−H activation at another nitrogen substituent and remote C−C bond formation to generate biologically relevant isoindolines and β‐lactams. The product selectivity is influenced by the employed ligand, with NHCs favoring the product of remote C−C coupling against products arising from direct C−C coupling and N‐demethylation.