Highly 2,3‐Selective Polymerization of Phenylallene and Its Derivatives with Rare‐Earth Metal Catalysts: From Amorphous to Crystalline Products

• Published in: Angewandte Chemie International Edition Vol. 56; no. 46; pp. 14653 - 14657
• Main Authors: Lin, Fei, Liu, Zhaohe, Wang, Tiantian, Cui, Dongmei
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 13.11.2017
• Edition: International ed. in English
• Subjects: Allene; Catalysts; Coordination compounds; Crystal structure; crystalline polymers; Crystallinity; Derivatives; Metal complexes; polyallene; Polymerization; Polymers; Rare earth elements; rare-earth catalysts; Scandium; selective polymerization; Selectivity; Yttrium; crystalline polymers; allene; rare-earth catalysts; selective polymerization; polyallene
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201707601

Rare‐earth metal complexes (Flu‐CH2‐Py)Ln(CH2SiMe3)2(THF)n (Ln=Sc(1), Lu(2), Tm(3), Y(4) and Gd(5)), upon the activation of [Ph3C][B(C6F5)4] and AliBu3, were employed to catalyze the polymerization of allene derivatives under mild conditions. The Gd, Y, Tm, Lu metal based precursors exhibited distinguished 2,3‐selectivity (>99.9 %) for phenylallene (PA) polymerization, whereas the smallest Sc metal based precursor showed a moderate 2,3‐selectivity. The activity increased with the central metal size following the trend of Gd(5)>Tm(4)>Y(3)>Lu(2)>Sc(1). Moreover, Gd(5) also realized the purely 2,3‐selective polymerizations of polar or nonpolar allene derivatives, para‐methylphenylallene, para‐flourophenylallene and para‐methoxyphenylallene, regardless of electron‐donating or ‐withdrawing substituents. Owing to the highly regular backbones, these polymers (except PPA) were crystalline, thus being the first crystalline polymers based on allene derivatives. Rare‐earth metal complexes (Flu‐CH2‐Py)Ln(CH2SiMe3)2(THF)n (Ln=Sc, Lu, Tm, Y and Gd), upon the activation of [Ph3C][B(C6F5)4] and AliBu3, were employed to catalyze the 2,3‐selective polymerization of phenylallene (PA) and its derivatives bearing polar or nonpolar substituent groups. Owing to the highly regular backbones, most obtained polymers were crystalline, thus being the first crystalline polymers based on allene derivatives.