Organocatalytic stereoselective ring-opening polymerization of lactide with dimeric phosphazene bases

被引：208

作者：

Zhang, Lei

Nederberg, Fredrik

Messman, Jamie M.

Pratt, Russell C.

Hedrick, James L.

Wade, Charles G.

机构：

[1] IBM Corp, Almaden Res Ctr, San Jose, CA 95120 USA

[2] Oak Ridge Natl Lab, Ctr Nanophase Mat Sci, Oak Ridge, TN 37831 USA

来源：

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY | 2007年 / 129卷 / 42期

关键词：

D O I：

10.1021/ja074131c

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Highly isotactic polylactide with a high melting temperature was synthesized from rac-lacticle through an organocatalytic route using dimeric phosphazene base 1-tert -butyl-2,2,4,4,4-pentakis(dimethylamino)-2 Delta(5),4 Delta(5)-catenadi(phosphazene) (P-2-t -Bu) catalyst at low temperature. Microstructural analysis of the prepared polymer using homodecoupled H-1 NMR spectroscopy revealed the formation of a stereoblock architecture containing long isotactic sequence of R and S blocks in the main chain. A proposed mechanism involving chain-end control and stereoerror explains the stereoselective polymerization.

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页码：12610 / +

页数：3

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