Stereoselective ROP of rac- and meso-Lactides Using Achiral TBD as Catalyst

Moins, Sébastien; Hoyas, Sébastien; Lemaur, Vincent; Orhan, Beste; Chiaie, Kayla R. Delle; Lazzaroni, Roberto; Taton, Daniel; Dove, Andrew P.; Coulembier, Olivier

doi:10.3390/catal10060620

Cited by 17 publications

(16 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In addition, evidence of a small amount of cyclization product was also detected by MALDI-TOF mass analysis. The regular m/z = 72 difference between the peaks indicated that significant transesterification took place during the polymerization process, which is consistent with TBD [25]. However, in some cases, transesterification could be used as well.…”

Section: Resultssupporting

confidence: 78%

“…However, to obtain stereocontrolled PLAs with TBD, cryogenic conditions were required ( P m = 0.58 at 23 °C 0.80 at –75 °C) to control the insertion of the monomer and reduce the side reaction (transesterification and epimerization reaction, etc.) [ 25 ]. Sterically crowded catalysts with a chiral center offer highly stereoselective polymers in the aforementioned organocatalysts for the stereoselective ROP of rac -LA.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Chiral 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD)-Catalyzed Stereoselective Ring-Opening Polymerization of rac-Lactide: High Reactivity for Isotactic Enriched Polylactides (PLAs)

Mahmood

Zhou

et al. 2020

Polymers

View full text Add to dashboard Cite

Chiral 4,8-diphenyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (DiPh-TBD) was synthesized and applied to a ring-opening polymerization of rac-lactide (rac-LA). The chiral DiPh-TBD promoted the synthesis of isotactic enriched polylactides (PLAs) with controlled molecular weight and narrow molecular weight distributions under mild, metal-free conditions. When the [rac-LA]/[Cat.] ratio was 100/1, full monomer conversion was achieved within only 1 min and a moderate probability of 0.67 meso dyads (Pm) was obtained at room temperature. A chain-end control mechanism (CEC) was found to be responsible for the isoselectivity based on the homodecoupled 1H NMR spectrum, the chiral HPLC measurement, and kinetic studies.

show abstract

Section: Resultssupporting

confidence: 78%

Section: Introductionmentioning

confidence: 99%

Chiral 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD)-Catalyzed Stereoselective Ring-Opening Polymerization of rac-Lactide: High Reactivity for Isotactic Enriched Polylactides (PLAs)

Mahmood

Zhou

et al. 2020

Polymers

View full text Add to dashboard Cite

show abstract

“…A primary strategy for the construction of well-defined glucose-based polycarbonates has involved controlled ROPs . The guanidine organocatalyst, TBD, has been applied widely for the ROP for a variety of cyclic monomers in the presence of alcohol or amine initiators, while exerting high reactivity and excellent control of polymer molar mass and dispersity. − More recently, regioselectivity has been observed using TBD during the ring-opening of cyclic carbonates and sugar-based fused-cyclic monomers. , Despite the importance of regiochemistry in directing synthesis, regulating properties, and thereby affecting polymer performance and applications, studies have seldom focused on revealing the regiochemical structures of the complex glucose-based polymers.…”

Section: Introductionmentioning

confidence: 99%

Invoking Side-Chain Functionality for the Mediation of Regioselectivity during Ring-Opening Polymerization of Glucose Carbonates

et al. 2020

View full text Add to dashboard Cite

The extent of participation of side-chain functionalities during the 1,5,7-triazabicyclo[5.4.0]dec-5-ene (TBD) organobase-catalyzed ring-opening polymerizations (ROP) of six-membered cyclic d-glucose-based carbonates was found to result in significantly different regiochemical outcomes. High regioselectivity was observed for naturally derived poly(4,6-d-glucose carbonate)s (PGCs) containing carbonate side chain substituents in the 2- and 3-positions, whereas regioirregularity was found for analogous PGCs with ether side-chain substituents. The backbone connectivities and structural details of these PGCs were examined through a combination of comprehensive 1D and 2D NMR studies on unimers and dimers, verifying the ring-opening preferences and indicating the contribution of side-chain functionalities in regioselective ROP processes. A molecular understanding of the curious role of side-chain functionalities was demonstrated via density functional theory calculations, revealing stabilization effects of intermolecular hydrogen bonding between the side-chain functionalities and TBD in the transition states. Overall, this work provides fundamental insights into the organocatalytic ROP of these specific six-membered asymmetric cyclic glucose carbonates. More importantly, these findings serve as a foundation for future design strategies that incorporate adjacent functionalities within monomers to act as directing groups and impart molecular interactions that define regiochemical ring-opening.

show abstract

“…On the other hand, chiral organocatalysts including binaphthol‐type phosphoric acids, [107] or a β‐isocupreidine/thiourea/chiral binaphthylamine, [108] have also been investigated. In a more recent report, Columbier et al., reported the ability of achiral TBD to produce greatly isotactic PLA from rac ‐LA at −75 °C [109] . Both chiral and achiral catalysts showed excellent stereocontrol; however, the ROP reactions are generally conducted at low temperatures which limits their use.…”

Section: Burgeoning Areas In Organocatalyzed and Other Transition‐met...mentioning

confidence: 99%

Spotting Trends in Organocatalyzed and Other Organomediated (De)polymerizations and Polymer Functionalizations

et al. 2022

View full text Add to dashboard Cite

Organocatalysis has evolved into an effective complement to metal‐ or enzyme‐based catalysis in polymerization, polymer functionalization, and depolymerization. The ease of removal and greater sustainability of organocatalysts relative to transition‐metal‐based ones has spurred development in specialty applications, e.g., medical devices, drug delivery, optoelectronics. Despite this, the use of organocatalysis and other organomediated reactions in polymer chemistry is still rapidly developing, and we envisage their rapidly growing application in nascent areas such as controlled radical polymerization, additive manufacturing, and chemical recycling in the coming years. In this Review, we describe ten trending areas where we anticipate paradigm shifts resulting from novel organocatalysts and other transition‐metal‐free conditions. We highlight opportunities and challenges and detail how new discoveries could lead to previously inaccessible functional materials and a potentially circular plastics economy.

show abstract

Stereoselective ROP of rac- and meso-Lactides Using Achiral TBD as Catalyst

Cited by 17 publications

References 25 publications

Chiral 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD)-Catalyzed Stereoselective Ring-Opening Polymerization of rac-Lactide: High Reactivity for Isotactic Enriched Polylactides (PLAs)

Chiral 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD)-Catalyzed Stereoselective Ring-Opening Polymerization of rac-Lactide: High Reactivity for Isotactic Enriched Polylactides (PLAs)

Invoking Side-Chain Functionality for the Mediation of Regioselectivity during Ring-Opening Polymerization of Glucose Carbonates

Spotting Trends in Organocatalyzed and Other Organomediated (De)polymerizations and Polymer Functionalizations

Contact Info

Product

Resources

About