105337-82-4Relevant articles and documents
Understanding the Use of Phosphine-(EWO) Ligands in Negishi Cross-Coupling: Experimental and Density Functional Theory Mechanistic Study
Gioria, Estefanía,del Pozo, Juan,Lledós, Agustí,Espinet, Pablo
, p. 2272 - 2282 (2021)
The easily prepared hemilabile ligand 1-(PPh2),2-(trans-CH═CHCOPh)-C6F4(PhPEWO-F) and other PEWO ligands are well-known promoters of C-C reductive eliminations and very effective in Negishi couplings. As an example, the efficient Negishi coupling of (C6F5)-I and Zn(C6F5)2is reported. The thorough experimental study of the steps involved in the catalytic cycle uncovers the potential weakness of this ligand that could frustrate at some points the desired cycle and provide some simple precautions to keep the catalytic cycle working efficiently. Density functional theory (DFT) calculations complete the experimental study and provide insight into nonobservable transition states and intermediates, comparing the potential conflict between reductive elimination and olefin insertion. Our results showcase the importance the transmetalation step, facilitated by the strong trans effect of the electron-withdrawing ligand, and the choice of organozinc nucleophiles, critical to ensure fast group exchange and a positive outcome of the catalytic reactions.
Pincer thioamide and pincer thioimide palladium complexes catalyze highly efficient negishi coupling of primary and secondary alkyl zinc reagents at room temperature
Wang, Haibo,Liu, Jing,Deng, Yi,Min, Tianyin,Yu, Ganxiang,Wu, Xiaojun,Yang, Zhen,Lei, Aiwen
supporting information; scheme or table, p. 1499 - 1507 (2009/08/07)
Pincer thioamide PdII complex 2 was prepared, and its reaction with cyclohexylzinc chloride yielded novel pincer thioimide PdII complex 3 besides Pd0 species. The structures of complexes 2 and 3 were confirmed by X-ray ana
An electron-deficient diene as ligand for palladium-catalyzed cross-coupling reactions: An efficient alkylation of aryl iodides by primary and secondary alkylzinc reagents
Liu, Qiang,Duan, Hui,Luo, Xiancai,Tang, Yang,Li, Gang,Huang, Rong,Lei, Aiwen
supporting information; experimental part, p. 1349 - 1354 (2009/05/30)
An electron-deficient diene, L1, was found to be an effective ligand in facilitating palladium-catalyzed Negishi couplings involving primary and secondary alkylzinc reagents. The reactions took place readily at 60 °C in THF with 5 mol% of a catalyst generated in situ from bis(acetonitrile) palladium dichloride [PdCl2(MeCN)2] and L1, and functional groups such as chloro, bromo, etc. attached to phenyl ring as well as β-H atoms adjacent to the reaction site were well tolerated. The problematic isomerizations in secondary alkyzinc reagents involved in the reactions reported in the literature were also observed in our system when isopropylzinc chloride was employed alone as the nucleophile. However, the isomerization was significantly suppressed when i-Pr2Zn was utilized in the presence of L1.
