The goal of this work was to synthesize substituted polystyrene for metal extraction and/or depollution by introduction of substituted piperazines as chelatants starting from Merrifield polymer. After transformation of Merrifield’s resin in azidomethyl polystyrene, click-chemistry using copper (I)-catalyzed Huisgen’s reaction (CuAAC) was performed to prepare different polymers grafted with 1,4-...

s: (there may be repeats in here) Excerpt from: Quinolone Molecular Structure-Activity Relationships: What We Have Learned about Improving Antimicrobial Activity

This paper describes the synthesis of several new series of 1-(2-aryldiazen-1-yl-) 4-arylpiperazines and 1-(2aryldiazen-1-yl-)4-arylalkylpiperazines by using diazonium coupling between arenediazonium ions with the appropriate 1-arylpiperazine or the 1-arylalkylpiperazine. The new compounds have a common thread in that they are isomers of the series of N-(2,3-dimethylphenyl)N’-(aryldiazenyl)-pip...

We report here a novel method for the modular synthesis of highly substituted piperazines and related bis-nitrogen heterocycles via a palladium-catalyzed cyclization reaction. The process couples two of the carbons of a propargyl unit with various diamine components to provide nitrogen heterocycles in generally good to excellent yields and high regio- and stereochemical control.

We report a mild and environmentally benign method for the synthesis of tertiary amines using alcohols as the alkylating reagents. Not only secondary amines such as piperazines but also amino acids and amino alcohols can be N-alkylated selectively. For N,O-benzyl protected amino alcohols, both N,O-de-benzylation and N-methylation were achieved in one-pot.

Use of a base-free Pd(DMSO)(2)(TFA)(2) catalyst system enables the synthesis of six-membered nitrogen heterocycles via a Wacker-type aerobic oxidative cyclization of alkenes bearing tethered sulfonamides. Various heterocycles, including morpholines, piperidines, piperazines, and piperazinones, are accessible by this method.

The development of more active C-H oxidation catalysts has inspired a rapid, scalable, and stereoselective assembly of multifunctional piperazines through a [3+3] coupling of azomethine ylides. A combination of visible-light irradiation and aluminum organometallics is essential to promote this transformation, which introduces visible-light photochemistry of main-group organometallics and sets t...