Zinc-Mediated One-Pot Tandem Reaction of Nitriles with Propargyl Bromides: An Access to 3-Alkynylpyridines

Palladium-Catalyzed Cascade Reactions of δ-Ketonitriles with Arylboronic Acids: Synthesis of Pyridines

This study presents the first example of the Pd-catalyzed cascade reactions of 5-oxohexanenitrile with arylboronic acids, affording important synthon 2-methylpyridines that can be further translated through C(sp³)-H functionalization to construct pyridine derivatives. Furthermore, this chemistry allows 5-oxo-5-arylpentanenitrile to react with arylboronic acids to provide unsymmetrical 2,6-diarylpyridines. This protocol paves the way for the practical and atom economical syntheses of valuable pyridines with broad functional groups in moderate to excellent yields under mild conditions.

Copper-Catalyzed Ring-Expansion Cascade of Azirines with Alkynes: Synthesis of Multisubstituted Pyridines at Room Temperature

The first intermolecular ring-expansion cascade of azirines with alkynes for the synthesis of pyridines, enabled by a copper/triethylamine catalytic system via simultaneous generation and utilization of yne-enamine and skipped-yne-imine intermediates, is reported. Experimental as well as computational mechanistic studies revealed that the role of triethylamine is crucial in deciding the reaction pathway toward the pyridine products. This process offers a novel, one-step, direct, and practical strategy for the rapid construction of highly substituted pyridines under exceedingly mild conditions, and an installed alkyne functionality.

Facile synthesis of heavily-substituted alkynylpyridines via a Sonogashira approach

A robust synthesis of highly-substituted alkynylpyridines via a Sonogashira approach is described, providing a library of functionalized pyridines for biological studies.

Phosphonium-based aminophosphines as bifunctional ligands for sequential catalysis of one-pot hydroformylation–acetalization of olefins

A series of ionic phosphonium-based aminophosphinesL1–L3were prepared and fully characterized, in each of which the involved bifunctional moieties of the phosphine fragment and Lewis acidic phosphonium were linked together by stable chemical bonds and bridged by one N-atom.