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.

Charge-altering releasable transporters (CARTs) for the delivery and release of mRNA in living animals

“…When the CART/mRNA complexes are added to unbuffered water, sizes remain at 257 ± 24 nm over the full 2-h experiment (SI Appendix, Fig. S4A), consistent with previous observations that α-amino ester homooligomers do not rearrange under these conditions (41). Zeta potential measurements are in line with particle size data, with surface charge starting at + 33 ± 7 mV and evolving to -30 ± 3 mV over 2 h (SI Appendix, Fig.…”

“…Organocatalytic ring-opening polymerization (OROP) is an excellent method for the preparation of functionalized biomaterials. OROP provides expedient access to oligomers of low dispersity, avoids metal contaminants associated with some polymerization methods, provides precise control over chain length by varying the ratio of initiator to monomer, and allows for the incorporation of multiple monomer functionalities through cooligomerization (38)(39)(40)(41). We have previously reported the synthesis of poly(α-amino ester)s (Fig.…”

A Simple and Facile Approach to Aliphatic N-Substituted Functional Eight-Membered Cyclic Carbonates and Their Organocatalytic Polymerization

“…In our continued efforts towards the development of functional carbonate monomers, we have explored the use of N-substituted diethanolamines (DEAs) as inexpensive and readily available 31 starting materials 32 for the synthesis and subsequent polymerization of aliphatic N-substituted eight-membered cyclic carbonate monomers. Functional 8-membered cyclic carbonates were synthesized via intramolecular cyclization of the 1,5-diol of N-substituted DEAs and subsequently polymerized via organo-catalytic ROP to access new functional aliphatic 4 N-substituted polycarbonates.…”

“…TMC). To this end, we computed isodesmic measures for the enthalpies of ringopening 44,45 for (2') and (2a)32,46 and compared them with that of TMC. An exhaustive conformer search for the products of the isodesmic reactions (see Figures S13 and S14, Supporting…”

Combining Sustainable Polymerization Routes for the Preparation of Polyesters, Polycarbonates, and Copolymers

“…It is notable that β-malolactatonates, monomers which are difficult to homopolymerize using ROP, have recently been copolymerized with other cyclic esters and carbonates as a route to polyhydroxyalkanoates (PHA) (8,9). Indeed, the synthesis of new cyclic esters (10,11) and cyclic carbonates for use in ROP is an important field (12-14).…”