An improved synthesis of N-aryl and N-heteroaryl substituted homopiperazines—from conventional thermal conditions to scaling-up using microwave heating
An efficient Pd(0)-catalyzed Buchwald-Hartwig protocol for the facile preparation of N-aryl and N-heteroaryl substituted homopiperazines is described. The syntheses proceeded with aryl- and heteroaryl halides in high yields using X-Phos as best ligand. The C-N coupling products were prepared both under conventional as well as microwave heating conditions and examples for microwave-assisted upscaling are included in this study. (C) 2009 Elsevier Ltd. All rights reserved.
Nickel-Catalyzed Decarboxylation of Aryl Carbamates for Converting Phenols into Aromatic Amines
to accessing aromaticamines from an abundant feedstock, namely phenols. The most reliable catalytic method for converting phenols to aromaticamines uses an activating group, such as a trifluoromethane sulfonyl group. However, this activating group is eliminated as a leaving group during the amination process, resulting in significant waste. Our nickel-catalyzed decarboxylation reaction of aryl carbamates