Electric Literature of C20H20BrPIn 2022 ,《Enantio- and Regioselective Ni-Catalyzed para-C-H Alkylation of Pyridines with Styrenes via Intermolecular Hydroarylation》 appeared in Journal of the American Chemical Society. The author of the article were Ma, Jun-Bao; Zhao, Xia; Zhang, Dongju; Shi, Shi-Liang. The article conveys some information:
Herein the first enantioselective para-C-H activation of pyridines through the use of a Ni-Al bimetallic catalyst system and N-heterocyclic carbene (NHC) ligand for intermol. hydroarylation of styrenes was described. The reaction proceeded in high to excellent enantioselectivities (up to 98.5:1.5 er) and high site-selectivities for both styrene and pyridine components (up to >98:2). Consequently, a broad range of enantioenriched 1,1-diarylalkanes containing pyridine moieties could be prepared in a single step with 100% atom economy. Computational studies supported a mechanism involving a ligand-to-ligand H-transfer (LLHT) and reductive elimination sequence, with LLHT being the rate- and enantioselectivity-determining step. DFT studies indicated that the π-π stacking interaction between the NHC aryl fragment and trans-styrenes was critical for high reactivity and enantiocontrol.Ethyltriphenylphosphonium bromide(cas: 1530-32-1Electric Literature of C20H20BrP) was used in this study.
Ethyltriphenylphosphonium bromide(cas: 1530-32-1) is a phase transfer catalyst, used to accelerate the cure of phenolic-based epoxy resins, certain fluoroelastomer resins and thermosetting powder coatings. CatOnium ETPB is also used as catalysts in the synthesis of certain organic compounds.Electric Literature of C20H20BrP
Referemce:
Bromide – Wikipedia,
bromide – Wiktionary