Peh, Guang-Rong; Kantchev, Eric Assen B.; Zhang, Chi; Ying, Jackie Y. published the artcile< N-Heterocycle carbene (NHC)-ligated cyclopalladated N,N-dimethylbenzylamine: A highly active, practical and versatile catalyst for the Heck-Mizoroki reaction>, SDS of cas: 1003-21-0, the main research area is palladium dimethylbenzylamine mesitylimidazolylidene catalyst Heck.
A protocol for the Heck-Mizoroki reaction mediated by cyclopalladated N,N-dimethylbenzylamine ligated with a N-heterocyclic carbene, 1,3-bis(mesityl)imidazol-2-ylidene (IMes), is reported. The precatalyst can be synthesized on ∼100 g scale by a tri-component, sequential, one-pot reaction of N,N-dimethylbenzylamine, PdCl2 and IMes·HCl in refluxing acetonitrile in air in the presence of K2CO3. This single component catalyst is stable to air, moisture and long term storage and can be conveniently dispensed as a stock solution in NMP. It mediates the Heck-Mizoroki reaction of a range of aryl and heteroaryl bromides in reagent grade NMP at the 0.1-2 mol% range without the need for rigorous anhydrous techniques or a glove box, and is active even in air. The catalyst is capable of achieving very high levels of catalytic activity (TON of up to 5.22 × 105) for the coupling of a deactivated aryl bromide, p-bromoanisole, with tert.-Bu acrylate as a benchmark substrate pair. A wide range of aryl bromides, iodides and, for the first time with a NHC-Pd catalyst, a triflate was coupled with diverse acrylate derivatives (nitrile, tert-Bu ester and amides) and styrene derivatives The use of excess (>2 equivalent) of the aryl bromide and tert-Bu acrylate leads to mixture of tert-Bu β,β-diarylacrylate and tert-Bu cinnamate derivatives depending on the substitution pattern of the aryl bromide. Electron rich m- and p-substituted aryl bromides give the diarylated products exclusively, whereas electron-poor aryl bromides give predominantly mono-arylated products. For o-substituted aryl bromides, no doubly arylated products could be obtained under any conditions. Overall, the active catalyst (IMes-Pd) shows higher activity with electron-rich aryl halides, a marked difference compared with the more commonly used phosphane-Pd or non-ligated Pd catalysts.
Organic & Biomolecular Chemistry published new progress about Heck reaction. 1003-21-0 belongs to class imidazoles-derivatives, and the molecular formula is C4H5BrN2, SDS of cas: 1003-21-0.
Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem