A base-mediated tandem aza-Michael addition–vinylogous nitroaldol condensation has been described between 3,5-dialkyl 4-nitropyrazoles and alkynyl ketones/aldehydes. This transition metal-free atom economical transformation occurred via C–N and C═C bond formations in one step with the elimination of water. The construction of a variety of highly substituted N-fused 3-nitropyrazolopyridine derivatives
Straightforward Novel One-Pot Enaminone and Pyrimidine Syntheses by Coupling-Addition-Cyclocondensation Sequences
作者:Thomas J. Müller、Alexei S. Karpov
DOI:10.1055/s-2003-42480
日期:——
The coupling of acid chlorides 1 with terminal alkynes 2using only one equivalent (!) of triethylamine under Sonogashira conditions followed by subsequent addition of primary or secondary amines 4 to the intermediate alkynones 3 represents a straightforward one-pot three component access to enaminones 5 undermildconditions and in excellent yields. Furthermore, 2,4-di- and 2,4,6-trisubstituted pyrimidines
In the presence of 1-(2-pyridylethynyl)-2-(2-thienylethynyl)benzene as a ligand, the direct synthesis of alkynones has accomplished by a Pd-catalyzed coupling reaction of acid chlorides with terminal acetylenes under mild conditions.
The direct acyl Sonogashira cross-coupling of carboxylic acids with terminal alkynes has been achieved through Pd/Cu cooperative catalysis. In this reaction, the readily available carboxylic acids act as the acyl source for the coupling with various terminal alkynes to produce highly valuable ynones in good to high yields. The reaction features high chemoselectivity and functional group tolerance.
A Pd–Sn heterobimetallic catalyst for carbonylative Suzuki, Sonogashira and aminocarbonylation reactions using chloroform as a CO surrogate
作者:Anuradha Mohanty、Mukesh Kumar Nayak、Sujit Roy
DOI:10.1039/d3ob00676j
日期:——
heterobimetallic Pd–Sn catalyst for the carbonylative Suzuki coupling, aminocarbonylation reaction, and carbonylative Sonogashira coupling of aryl halides with boronic acids, amines, and aromatic alkynes leading to a three-component coupling reaction using in situ generated carbon monoxide. Under the optimized reaction conditions, a variety of bisaryl ketones, amides, and aromatic ynones have been synthesized