14897-78-0Relevant articles and documents
Semi-aromatic biobased polyesters derived from lignin and cyclic carbonates
Horn, Jessica,Locklin, Jason,Ring, John,White, Evan M.,Winfield, Demichael
supporting information, p. 9658 - 9668 (2021/12/09)
The synthesis of biobased aromatic polyesters from lignin-derived monomers has become well described in the literature, but robust extrusion, thermomechanical, tensile and degradation studies of these materials is lacking. In this work, we have systematically investigated the mechanical and biodegradation properties of semi-aromatic polyesters that can potentially be derived from lignin. AB monomers were synthesized from reduced analogues of coumaric, ferulic, and sinapic acids along with cyclic carbonates, where the synthetic methodology was assessed using E-Factor and EcoScale. Polymerization yielded both semi-crystalline and amorphous polyesters with mechanical properties varying over three orders of magnitude. Detailed characterization revealed a wide array of properties including a highly ductile thermoplastic, a strong and rigid thermoplastic, and an elastomer. Composting biodegradation tests showed both degradable and nondegradable polymers can be achieved in this class. This work demonstrates the versatility of this class of polymers and illustrates their potential to replace non-sustainably derived plastics. This journal is
Synthesis of Lactams via Ir-Catalyzed C-H Amidation Involving Ir-Nitrene Intermediates
Li, Xiaoxun,Liu, Jitian,Tang, Weiping,Wang, Shuojin,Ye, Wenjing,Zheng, Junrong
, (2020/03/19)
x-membered lactams were synthesized via either an amidation of sp3 C-H bonds or an electrophilic substitution of arenes via Ir-nitrene intermediates. With the employment of a readily available iridium catalyst in dichloromethane or hexafluoro-2-propanol, a wide range of lactams were synthesized in good to excellent yields with high selectivity.
Phenyl Esters Are Potent Inhibitors of Caseinolytic Protease P and Reveal a Stereogenic Switch for Deoligomerization
Hackl, Mathias W.,Lakemeyer, Markus,Dahmen, Maria,Glaser, Manuel,Pahl, Axel,Lorenz-Baath, Katrin,Menzel, Thomas,Sievers, Sonja,B?ttcher, Thomas,Antes, Iris,Waldmann, Herbert,Sieber, Stephan A.
supporting information, p. 8475 - 8483 (2015/07/15)
Caseinolytic protease P (ClpP) represents a central bacterial degradation machinery that is involved in cell homeostasis and pathogenicity. The functional role of ClpP has been studied by genetic knockouts and through the use of beta-lactones, which remain the only specific inhibitors of ClpP discovered to date. Beta-lactones have served as chemical tools to manipulate ClpP in several organisms; however, their potency, selectivity and stability is limited. Despite detailed structural insights into the composition and conformational flexibility of the ClpP active site, no rational efforts to design specific non-beta-lactone inhibitors have been reported to date. In this work, an unbiased screen of more than 137000 compounds was used to identify five phenyl ester compounds as highly potent ClpP inhibitors that were selective for bacterial, but not human ClpP. The potency of phenyl esters largely exceeded that of beta-lactones in ClpP peptidase and protease inhibition assays and displayed unique target selectivity in living S. aureus cells. Analytical studies revealed that while phenyl esters are cleaved like native peptide substrates, they remain covalently trapped as acyl-enzyme intermediates in the active site. The synthesis of 36 derivatives and subsequent structure-activity relationship (SAR) studies provided insights into conserved structural elements that are important for inhibition potency and acylation reactivity. Moreover, the stereochemistry of a methyl-substituent at the alpha position to the ester, resembling amino acid side chains in peptide substrates, impacted ClpP complex stability, causing either dissociation into heptamers or retention of the tetradecameric state. Mechanistic insights into this intriguing stereo switch and the phenyl ester binding mode were obtained by molecular docking experiments.
