title: Organocatalytic ring-opening polymerization of morpholinones: new strategies to functionalized polyesters.
abstract: 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.
authors.affiliation: Department of Chemistry, Stanford University , Stanford, California 94306, United States.
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Blake
authors.forename: Robert M
authors.initials: RM
authors.lastname: Waymouth
mesh_terms: D000588:Amines / Q000737:chemistry; D002384:Catalysis; D060326:Chemistry Techniques, Synthetic; D004983:Ethanolamines / Q000737:chemistry; D007783:Lactones / Q000737:chemistry; D015394:Molecular Structure; D060172:Morpholinos / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry; D011091:Polyesters / Q000138:chemical synthesis* / Q000737:chemistry; D058105:Polymerization; D012995:Solubility; D013816:Thermodynamics
chemical_list: D000588:Amines; D004983:Ethanolamines; D007783:Lactones; D060172:Morpholinos; D011091:Polyesters; D010165:Palladium; C020283:diethanolamine