Bench-Stable Nickel Precatalysts with Heck-type Activation

Herein, we report the synthesis and characterization of a new class of air- and moisture-stable phosphine-containing nickel­(II) precatalysts, which activate through a Heck-type mechanism. The activities of the precatalysts are demonstrated with a carbonyl–ene coupling reaction

Improved Synthesis of Mono- and Disubstituted 2‑Halonicotinonitriles from Alkylidene Malononitriles

Pyridines with 2,3,4 and/or 5 substitution remain challenging to prepare. Existing strategies to form multisubstituted 2-halonicotinonitriles via enamines suffer from dimerization of the starting alkylidene malononitriles resulting in low yields. Through alteration of reaction conditions, a new high yielding method into enamines was realized by condensing DMF–DMA and alkylidene malononitriles in the presence of substoichiometric acetic anhydride. Cyclization of the resulting enamines under Pinner conditions provided 2-halonicotinonitriles in high overall yields

Continuous Synthesis and Use of <i>N</i>‑Heterocyclic Carbene Copper(I) Complexes from Insoluble Cu₂O

It is demonstrated that homogeneous <i>N</i>-heterocyclic carbene–copper(I)-chloride complexes can be prepared continuously by flowing NHC precursors through a packed bed of solid Cu₂O suspended in molecular sieves. The method enables the synthesis of a wide range of complexes including those that are challenging to prepare using standard approaches. Our strategy enables both sustained output of complex production for long-term catalytic reactions (greater than 5 h) and for generation of gram quantities for storage (greater than 1 g of complex in ∼16 min)

Assessing Carbazole Derivatives as Single-Electron Photoreductants

The electron-donating capabilities of carbazoles have stimulated interest in their use as photoinduced single-electron reductants. Due to the modularity of the carbazole, a further broadening and understanding of their reactivity could be achieved by manipulating the structure. Herein, eight carbazole derivatives were synthesized, characterized, and assessed as single-electron photoreductants in the hydrodehalogenation of aryl halides and the arylation of N-methylpyrrole