<sup>31</sup>P NMR Spectroscopically Quantified Hydrogen-Bonding Strength of Thioureas and Their Catalytic Activity in Diels-Alder Reactions
作者:Alexander R. Nödling、Gergely Jakab、Peter R. Schreiner、Gerhard Hilt
DOI:10.1002/ejoc.201402871
日期:2014.10
the 31PNMR chemical shifts. A linear correlation between both variables was observed throughout the functionalized thioureas. The 31PNMR probe correlation fared better in comparison to a pKa correlation. Accordingly, the quantification presented herein by using a 31PNMR probe offers an elegant way to estimate the catalyticactivity of thiourea catalysts in hydrogen-bond-activated reactions such
Techniques regarding the synthesis of polyesters and/or polycarbonates through one or more ring-opening polymerizations conducted within a flow reactor and facilitated by a urea anion catalyst and/or a thiourea catalyst are provided. For example, one or more embodiments can comprise a method, which can comprise polymerizing, via a ring-opening polymerization within a flow reactor, a cyclic monomer in the presence an organocatalyst comprising a urea anion.
(Thio)urea Organocatalyst Equilibrium Acidities in DMSO
作者:Gergely Jakab、Carlo Tancon、Zhiguo Zhang、Katharina M. Lippert、Peter R. Schreiner
DOI:10.1021/ol300307c
日期:2012.4.6
Bordwell's method of overlapping indicators was used to determine the pK(a) values of some of the most popular (thio)urea organocatalysts via UV spectrophotometric titrations. The incremental effect of CF3 groups on acidic strength was also investigated. The pic's are in the range of 8.5-19.6. The results may lead to a better understanding of noncovalent organocatalysis and may aid in future catalyst development.
RING-OPENING POLYMERIZATIONS USING A FLOW REACTOR
申请人:International Business Machines Corporation
公开号:US20200407496A1
公开(公告)日:2020-12-31
Techniques regarding the synthesis of polyesters and/or polycarbonates through one or more ring-opening polymerizations conducted within a flow reactor and facilitated by a urea anion catalyst and/or a thiourea catalyst are provided. For example, one or more embodiments can comprise a method, which can comprise polymerizing, via a ring-opening polymerization within a flow reactor, a cyclic monomer in the presence an organocatalyst comprising a urea anion.
Synthesis, cytotoxicity and antimicrobial activity of thiourea derivatives incorporating 3-(trifluoromethyl)phenyl moiety
A total of 31 of thiourea derivatives was prepared reacting 3-(trifluoromethyl)aniline and commercial aliphatic and aromatic isothiocyanates. The yields varied from 35% to 82%. All compounds were evaluated in vitro for antimicrobial activity. Derivatives 3, 5, 6, 9, 15, 24 and 27 showed the highest inhibition against Gram-positive cocci (standard and hospital strains). The observed MIC values were