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Updated: Nov 22, 2025

Facile Preparation of 2Z,4E-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate
Published on: June 21, 2017
Unsymmetrical diarylamido-based rare-earth alkyl complexes: their synthesis and catalytic performance in isoprene
Wenhui Ren1, Hui Liu1, Fen You1
1Department of Polymer Materials, College of Materials Science and Engineering, Shanghai University, Materials Building, Nanchen Street 333, Shanghai 200444, China. xcshi@shu.edu.cn.
Abstract:
A family of rare-earth complexes bearing diarylamido-based pincer ligands with phosphino-, phenylthio- and quinolino-sidearms have been synthesized and fully characterized. Upon activation by [Ph3C][B(C6F5)4], the scandium (P-Sc and S-Sc) and yttrium complexes (P-Y and S-Y) could catalyze the polymerization of isoprene with cis-1,4 selectivity (up to 98.8%), while the lutetium analogues P-Lu and S-Lu produced trans-1,4 selective polyisoprene (up to 83.3%). Density functional theory (DFT) calculations were carried out to clarify the mechanisms for the metal-dependent stereoselective (cis to trans) polymerization of isoprene catalyzed by P-Sc, P-Y and P-Lu, suggesting that kinetically and thermodynamically more favorable insertion-isomerization during chain propagation is the key reason for P-Lu catalyzed trans-stereoselective isoprene polymerization.
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