New asymmetric vanadium catalyst for highly selective oxidative coupling polymerization
New asymmetric vanadium catalyst for highly selective oxidative coupling polymerization
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DOI：
10.1002/pola.21077
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发表时间：
2005-12-01
影响因子：
--
通讯作者：
Higashimura, H
中科院分区：
文献类型：
--
作者：
Habaue, S;Murakami, S;Higashimura, H
开发了一种新型钒氧双恶唑啉催化剂，如硫酸氧钒（VOSO 4）-（R）-2，2'-异亚丙基双（4-苯基-2-恶唑啉）[（R）Phbox]，用于2，3-二羟基萘的不对称氧化偶联聚合（AOCP）.例如，AOCP与VOSO 4-（R）Phbox在CH2Cl2-MeOH [7/1（v/v）]中在室温下在O-2气氛下持续24小时，随后羟基的乙酰化，以58%的产率得到聚合物，比旋光度为[α]（D）=-147。聚合过程中的对映选择性估计为80%对映体过量（S），该值远高于用铜（I）基催化剂体系和报道的用于不对称氧化偶联产生1，1 ′-联-2-萘酚衍生物的典型氧钒（IV）催化剂的聚合所观察到的值。(c)2005 Wiley Periodicals，Inc.
Novel oxovanadium(IV)-bisoxazoline catalysts, such as vanadyl sulfate (VOSO4)-(R)-2,2'-isopropylidenebis(4-phenyl-2-oxazoline) [(R)Phbox], for the asymmetric oxidative coupling polymerization (AOCP) of 2,3-dihydroxynaphthalene were developed. For example, the AOCP with VOSO4-(R)Phbox in CH2Cl2-MeOH [7/1 (v/v)] at room temperature for 24 h under an O-2 atmosphere, followed by acetylation of the hydroxyl groups, afforded a polymer in a 58% yield with a specific rotation of [alpha](D) = -147. The enantioselectivity during the polymerization was estimated to be 80% enantiomeric excess (S), a value much higher than that observed for the polymerizations with the copper(l)-based catalyst systems and the typical oxovanadium(IV) catalysts reported for the asymmetric oxidative coupling producing the 1,1'-bi-2-naphthol derivatives. (c) 2005 Wiley Periodicals, Inc.