A Reusable Palladium/Cationic 2,2′-Bipyridyl System-Catalyzed Double Mizoroki-Heck Reaction in Water

Abstract

A reusable PdCl 2 (NH 3 ) 2 /cationic 2,2 -bipyridyl system was used to catalyze the double Mizoroki-Heck reaction of aryl iodides with electron-deficient alkenes in water in the absence of inert gas, giving β,β-diarylated carbonyl derivatives in good to excellent yields. The formation of unsymmetrical β,β-diarylated alkenes were also studied by coupling aryl iodides with the corresponding aryl-substituted α,β-unsaturated carbonyl compounds. This water-soluble catalyst can be swiftly separated from the organic layer using simple extraction for the further reuse, and, thus, makes it an operationally-simple and environmentally-benign procedure.

Catalytic Direct Cyanomethylenation of C(sp3)–H Bonds via a One-Step Double C–C Bond Formation

“…However, quaternary phosphorus salts are employed in a stoichiometric quantity . Modern methods of synthesizing these compounds include the addition of cyanomethylene equivalents to ketones, the transition-metal-catalyzed cyanation of vinyl halides, the metal-based or metal-free cyanation of terminal olefins, the Suzuki reaction of haloacrylonitrile with arylboronic acids, the Heck reaction of acrylonitrile with an aryl halide, and the addition of arylboronic acid or heteroarene to cyanoalkynes . However, all methods demand substrates bearing reactive and preinstalled sp 2 - or sp-hybridized carbon centers.…”

Modular preparation of cationic bipyridines and azaarenes via C–H activation

“… 17 Likewise, Tsai and coworkers used this ligand for a palladium-catalyzed Mizoroki–Heck reaction under phase-transfer conditions. 18 Ertem, Manbeck, and coworkers have shown that even when the trimethylaminium is further separated from the metal center, the impact of the charge has beneficial properties on catalysis. 19 …”