Triclocarban: Commercial Antibacterial and Highly Effective H-Bond Donating Catalyst for Ring-Opening Polymerization

Abstract

The antibacterial compound, triclocarban (TCC), is shown to be a highly effective H-bond donating catalyst for ring-opening polymerization (ROP) when applied with an H-bond accepting base cocatalyst. These ROPs exhibit the characteristics of “living” polymerizations. TCC is shown to possess the high activity characteristic of urea (vs thiourea) H-bond donors. The urea class of H-bond donors is shown to remain highly active in H-bonding solvents, a trait that is not displayed by the corresponding thiourea H-bond donors. Two H-bond donating ureas that are electronically similar to TCC are evaluated for their efficacy in ROP, and a mechanism of action is proposed. This “off-the-shelf” H-bond donor is among the most active and most controlled organocatalysts for the ROP of lactones.

Solvent‐free ring‐opening polymerization of lactones with hydrogen‐bonding bisurea catalyst

“…Compared to the bifunctional catalysts, the advantage of hydrogen bond donor (HBD) in cooperation with a hydrogen bond acceptor (HBA) is a straightforward synthetic access from the commercial compounds. Kiesewetter and coworkers reported that the HBDs—urea and thiourea stand out among the controlled ROP of lactones, because of their precise controls for polymerization over transesterification . The urea HBD has better activity and controllability than the thiourea in the ROP of lactones (lactide excluded).…”

Polyester functional graphenic materials as a mechanically enhanced scaffold for tissue regeneration

“…Analysis and characterization of polyesters Polyesters (PCL, PLA, and PGA) were synthesized with low Đ and with targeted molecular weights via ring-opening polymerization. 38 Molecular weights and dispersities were analyzed by GPC, NMR, and XPS and were found to be comparable (Table 1). PCL and PLA molecular weights were most reliably determined by THF GPC; however, the molecular weight of PGA was determined most accurately by 1 H-NMR end-group analysis due to limited solubility in most solvents.…”

“…An organic coordination catalyst system was selected in order to avoid tin toxicity, while providing characteristics consistent with living polymerizations. 38 To verify that the polymerization was controlled, PCL was observed by 1 H-NMR to give a linear conversion to molecular weight (ESI Fig. S1 †).…”

“…Example ring-opening polymerization using 3-caprolactone PCL, PLA, and PGA were synthesized via a living ring-opening polymerization with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU, Alfa Aesar, Ward Hill, MA, USA) and 3,4,4 0 -trichlorocarbanilide (TCC) coordination co-catalysts. 38 In a typical PCL preparation, recrystallized TCC (1.25 mol eq.) was dissolved in 3-caprolactone (100 mol eq.)…”

High Molecular‐Weight Cyclic Polyesters from Solvent‐Free Ring‐Opening Polymerization of Lactones with a Pyridyl‐Urea/MTBD

“…In combination with a base, the binary catalytic systems exhibited an excellent performance in both activity and selectivity in the preparation of linear polymers. [ 41–46 ] However, it was still a challenge to prepare polyesters with high molecular weight based on the (thio)urea catalysts. To our knowledge, there were only few reports about the synthesis of polyesters with a molecular weight higher than 100 kg mol −1 with the (thio)urea systems.…”