Controlled Oxidation of Pyrroles: Synthesis of Highly Functionalized γ-Lactams
摘要:
The oxidation of pyrroles usually leads to uncontrolled polymerization and decomposition. To overcome this problem, the controlled oxidation of substituted pyrroles with Dess-Martin periodinane is reported. This strategy yields a range of 5-aroyloxypyrrolinones.
Mild Friedel–Crafts Reactions inside a Hexameric Resorcinarene Capsule: C−Cl Bond Activation through Hydrogen Bonding to Bridging Water Molecules
作者:Pellegrino La Manna、Carmen Talotta、Giuseppe Floresta、Margherita De Rosa、Annunziata Soriente、Antonio Rescifina、Carmine Gaeta、Placido Neri
DOI:10.1002/anie.201801642
日期:2018.5.4
Calculations showed that there are catalytically relevant hydrogen‐bonding interactions between the bridging water molecules of the capsule and benzyl chloride, which is fundamental for the activation of the C−Cl bond. The capsule controls the reaction outcome. Inside the inner cavity of the capsule, N‐methylpyrrole is preferentially benzylated in the unusual β‐position while mesitylene reacts faster than 1
Green, Mild, and Efficient Friedel–Crafts Benzylation of Scarcely Reactive Arenes and Heteroarenes under On‐Water Conditions
作者:Pellegrino La Manna、Annunziata Soriente、Margherita De Rosa、Antonio Buonerba、Carmen Talotta、Carmine Gaeta、Placido Neri
DOI:10.1002/cssc.201900137
日期:2019.4.23
The catalytic strategy exploits the hydrophobicity of the resorcinarene macrocycle 1 a. The proposed mechanism is based on the activation of benzylchloride by H‐bonding interactions with catalyst 1 a. In fact, under on‐water conditions the hydrophobic amplification of the strength of the H‐bonding interactions between the OH groups of the resorcinarene catalyst and the chlorine atom of benzyl chloride
β-Selective C–H Arylation of Pyrroles Leading to Concise Syntheses of Lamellarins C and I
作者:Kirika Ueda、Kazuma Amaike、Richard M. Maceiczyk、Kenichiro Itami、Junichiro Yamaguchi
DOI:10.1021/ja508449y
日期:2014.9.24
The first generalβ-selectiveC-Harylation of pyrroles has been developed by using a rhodium catalyst. This C-Harylation reaction, which is retrosynthetically straightforward but results in unusual regioselectivity, could result in de novo syntheses of pyrrole-derived natural products and pharmaceuticals. As such, we have successfully synthesized polycyclic marine pyrrole alkaloids, lamellarins C
Asymmetric synthesis of chiral trifluoromethylated heliotridane via highly catalytic asymmetric Friedel–Crafts alkylation with β-trifluoromethylated acrylates and pyrroles
Chiral Ph-dbfox (Ph-dbfox = (R,R)-4,6-dibenzofurandiyl-2,2â²-bis(4-phenyloxazoline))/Zn(NTf2)2 catalyzed enantioselective FriedelâCrafts reactions of β-CF3 acrylates with pyrroles and indoles have been investigated, which afforded the corresponding chiral trifluoromethyl pyrrole and indole derivatives in high yields (90â99%) with a range of 66â99% ee values. With the aid of the chiral adduct of the asymmetric FriedelâCrafts reaction, the chiral trifluoromethylated heliotridane has been successfully constructed in good total yield.
Gold(I)-Catalysed Hydroarylation of 1,3-Disubstituted Allenes with Efficient Axial-to-Point Chirality Transfer
作者:Daniel R. Sutherland、Luke Kinsman、Stuart M. Angiolini、Georgina M. Rosair、Ai-Lan Lee
DOI:10.1002/chem.201800209
日期:2018.5.11
Hydroarylation of enantioenriched 1,3‐disubstituted allenes has the potential to proceed with axial‐to‐point chirality transfer to yield enantioenriched allylated (hetero)aryl compounds. However, the gold‐catalysed intermolecular reaction was previously reported to occur with no chirality transfer owing to competing allene racemisation. Herein, we describe the development of the first intermolecular hydroarylations