Polymer-Grafted Ti−TADDOL Complexes. Preparation and Use as Catalysts in Diels−Alder Reactions
作者:Belen Altava、M. Isabel Burguete、Beatriz Escuder、Santiago V. Luis、Rosa V. Salvador、José M. Fraile、José A. Mayoral、Ana J. Royo
DOI:10.1021/jo961454a
日期:1997.5.1
of this functional group in PS-DVB polymers with different loading and cross-linking degrees, as well as on SMOP resins. These functionalized resins have been used to prepare Ti-TADDOL-supported complexes which have been tested as catalysts in the reaction of cyclopentadiene with 3-crotonoyl-1,3-oxazolidin-2-one. Although all the polymers obtained efficiently catalyze the reaction, only the one prepared
已经评估了用于制备用包含α,α,α′,α′-四芳基-1,3-二氧戊环-4,5-二甲醇(TADDOL)结构的手性片段官能化的聚合物的不同策略。当在溶液中制备含OH酚基(17和18)的TADDOL衍生物,然后通过在含有NaH和少量18C6和NBu(4)I的THF中反应选择性地锚定至氯甲基化聚合物时,可获得最佳结果。具有所需功能的树脂19已经以此方式制备。该程序允许在具有不同负载和交联度的PS-DVB聚合物中以及在SMOP树脂上有效引入该官能团。这些官能化的树脂已用于制备Ti-TADDOL负载的配合物,该配合物已在环戊二烯与3-巴豆酰基-1,3-恶唑烷二-2-酮的反应中作为催化剂进行了测试。尽管获得的所有聚合物均有效地催化了该反应,但是仅由α,α,α′,α′-四,3,5-二甲基苯基-1,3-二氧戊环-4,5-二甲醇制得的聚合物引起不对称性。