Department of Chemistry, Stanford University , Stanford, California 94306, United States.
J Am Chem Soc. 2014 Jul 2;136(26):9252-5. doi: 10.1021/ja503830c. Epub 2014 Jun 19.
The oxidative lactonization of N-substituted diethanolamines with the Pd catalyst [LPd(OAc)]2(2+)[OTf(-)]2 generates N-substituted morpholin-2-ones. The organocatalytic ring-opening polymerization of N-acyl morpholin-2-ones occurs readily to generate functionalized poly(aminoesters) with N-acylated amines in the polyester backbone. The thermodynamics of the ring-opening polymerization depends sensitively on the hybridization of the nitrogen of the heterocyclic lactone. N-Acyl morpholin-2-ones polymerize readily to generate polymorpholinones, but the N-aryl or N-alkyl substituted morpholin-2-ones do not polymerize. Experimental and theoretical studies reveal that the thermodynamics of ring opening correlates to the degree of pyramidalization of the endocyclic N-atom. Deprotection of the poly(N-Boc-morpholin-2-one) yields a water-soluble, cationic polymorpholinone.
N-取代的二乙醇胺与 Pd 催化剂[LPd(OAc)]2(2+)[OTf(-)]2发生氧化内酯化反应，生成 N-取代的吗啉-2-酮。N-酰基吗啉-2-酮的有机催化开环聚合反应很容易发生，在聚酯主链中生成带有 N-酰化胺的功能化聚（氨基酯）。开环聚合反应的热力学性质对杂环内酯氮的杂化状态非常敏感。N-酰基吗啉-2-酮很容易聚合生成聚吗啉酮，但 N-芳基或 N-烷基取代的吗啉-2-酮则不聚合。实验和理论研究表明，开环的热力学性质与环内 N-原子的三角化程度相关。聚（N-Boc-吗啉-2-酮）的脱保护反应生成了一种水溶性的、阳离子型的聚吗啉酮。
