Yuan Jia

All Publications

• Highly Selective O-Phenylene Bisurea Catalysts for ROP: Stabilization of Oxyanion Transition State by a Semiflexible Hydrogen Bond Pocket. Journal of the American Chemical Society Zhang, J., Lui, K. H., Zunino, R., Jia, Y., Morodo, R., Warlin, N., Hedrick, J. L., Talarico, G., Waymouth, R. M. 2024

  Abstract

  Organocatalyzed ring-opening polymerization (ROP) is a versatile technique for synthesizing biodegradable polymers, including polyesters and polycarbonates. We introduce o-phenylene bisurea (OPBU) (di)anions as a novel class of organocatalysts that are fast, easily tunable, mildly basic, and exceptionally selective. These catalysts surpass previous generations, such as thiourea, urea, and TBD, in selectivity (kp/ktr) by 8 to 120 times. OPBU catalysts facilitate the ROP of various monomers, achieving high conversions (>95%) in seconds to minutes, producing polymers with precise molecular weights and very low dispersities (Đ ≈ 1.01). This performance nearly matches the ideal distribution expected from living polymerization (Poisson distribution). Density functional theory (DFT) calculations reveal that the catalysts stabilize the oxyanion transition state via a hydrogen bond pocket similar to the "oxyanion hole" in enzymatic catalysis. Both experimental and theoretical analyses highlight the critical role of the semirigid o-phenylene linker in creating a hydrogen bond pocket that is tight yet flexible enough to accommodate the oxyanion transition state effectively. These new insights have provided a new class of organic catalysts whose accessibility, moderate basicity, excellent solubility, and unparalleled selectivity and tunability open up new opportunities for controlled polymer synthesis.

  View details for DOI 10.1021/jacs.4c04740

  View details for PubMedID 39102651

• Contrasting Roles of Counterions in Anionic Ring-Opening Polymerization Mediated by Heterocycle Organocatalysts ACS CATALYSIS Zhang, J., Lui, K., Jadrich, C. N., Jia, Y., Arrechea, P. L., Hedrick, J. L., Waymouth, R. M. 2023; 13 (24): 16097-16104

  View details for DOI 10.1021/acscatal.3c04772

  View details for Web of Science ID 001142879500001

• Flyby reaction trajectories: Chemical dynamics under extrinsic force. Science (New York, N.Y.) Liu, Y., Holm, S., Meisner, J., Jia, Y., Wu, Q., Woods, T. J., Martinez, T. J., Moore, J. S. 2021; 373 (6551): 208-212

  Abstract

  Dynamic effects are an important determinant of chemical reactivity and selectivity, but the deliberate manipulation of atomic motions during a chemical transformation is not straightforward. Here, we demonstrate that extrinsic force exerted upon cyclobutanes by stretching pendant polymer chains influences product selectivity through force-imparted nonstatistical dynamic effects on the stepwise ring-opening reaction. The high product stereoselectivity is quantified by carbon-13 labeling and shown to depend on external force, reactant stereochemistry, and intermediate stability. Computational modeling and simulations show that, besides altering energy barriers, the mechanical force activates reactive intramolecular motions nonstatistically, setting up "flyby trajectories" that advance directly to product without isomerization excursions. A mechanistic model incorporating nonstatistical dynamic effects accounts for isomer-dependent mechanochemical stereoselectivity.

  View details for DOI 10.1126/science.abi7609

  View details for PubMedID 34244412

• Architecture-Controlled Ring-Opening Polymerization for Dynamic Covalent Poly(disulfide)s JOURNAL OF THE AMERICAN CHEMICAL SOCIETY Liu, Y., Jia, Y., Wu, Q., Moore, J. S. 2019; 141 (43): 17075–80

  Abstract

  A strategy is reported for controlling the architecture of poly(disulfide)s by ring-opening polymerization. Aryl thiol initiators shift the ring-chain equilibrium to yield cyclic polymers, while alkyl thiols favor linear ones. Control over polymerization enables synthesis of large polymers (630 kDa) and catalytic depolymerization to recycle monomers. This work provides a new avenue to create dynamic covalent polymers with controlled geometry and length, allowing better characterization of structure-property relationships to expand their materials potentials.

  View details for DOI 10.1021/jacs.9b08957

  View details for Web of Science ID 000493866300008

  View details for PubMedID 31603692