Facile synthesis of stereoregular helical poly(phenyl isocyanide)s and poly(phenyl isocyanide)-block-poly(L-lactic acid) copolymers using alkylethynylpalladium(II) complexes as initiators
Facile synthesis of stereoregular helical poly(phenyl isocyanide)s and poly(phenyl isocyanide)-block-poly(L-lactic acid) copolymers using alkylethynylpalladium(II) complexes as initiators
复制标题
DOI：
10.1039/c5py00657k
复制
发表时间：
2015-06
影响因子：
4.6
通讯作者：
Jia-Li Chen;Ming‐Hsin Su;Zhi Jiang;Na Liu;Jun Yin;Yuanyuan Zhu;Zongquan Wu
中科院分区：
文献类型：
--
作者：
Jia-Li Chen;Ming‐Hsin Su;Zhi Jiang;Na Liu;Jun Yin;Yuanyuan Zhu;Zongquan Wu
开发新的合成方法以方便地以活体/可控的方式制备规整的立体规则螺旋多异氰酸酯及其嵌段共聚物是人们非常感兴趣的。在这一贡献中，意外地发现了一族空气稳定的烷基乙炔基Pd(II)络合物，促进了苯基异氰酸酯的活性聚合，得到了相对分子质量可控、相对分子质量分布窄、立体规整度高的聚苯基异氰酸酯S。有趣的是，这种烷基乙炔基钯(II)配合物在具有光学活性的苯基异氰酸酯的活性聚合中表现出很高的螺旋选择性，并选择性地合成了具有可控制螺旋选择性的单手螺旋聚苯基异氰酸酯。此外，含羟基的Pd(II)络合物可以在一锅内引发苯基异氰酸酯和L-丙交酯的活性聚合，形成高产率的聚苯基异氰酸酯-b-聚L-乳酸共聚物，其相对分子质量可控，组成可调。虽然这两种单体的聚合机理不同，但嵌段共聚是在活性/可控方式下进行的。
The development of novel synthetic methods for the facile preparation of well-defined stereoregular helical polyisocyanides and their block copolymers in a living/controlled fashion is of great interest. In this contribution, a family of air-stable alkylethynyl Pd(II) complexes was unexpectedly found to promote the living polymerization of phenyl isocyanide, affording poly(phenyl isocyanide)s with controlled molecular weights, narrow molecular weight distributions and high stereoregularity. Interestingly, such alkylethynyl Pd(II) complexes exhibit very high helix-sense-selectivity in the living polymerization of an optically active phenyl isocyanide bearing an L-alanine pendant with a long decyl chain, and a single handed helical poly(phenyl isocyanide) with controlled helical sense was selectively produced. Moreover, a Pd(II) complex bearing a hydroxyl group can initiate the living polymerization of both phenyl isocyanide and L-lactide in one-pot, leading to the formation of well-defined poly(phenyl isocyanide)-b-poly(L-lactic acid) copolymers in high yields with controlled molecular weights and tunable compositions. Although the two monomers were polymerized via distinct mechanisms, the block copolymerization was revealed to proceed under living/controlled manners.