The racemic title compound, C(17)H(23)N(3)O(3), isolated from the reaction of L-(-)-tyrosine hydrazide with triethyl orthopropionate in the presence of a catalytic quantity of p-toluenesulfonic acid (p-TsOH), crystallizes with Z' = 1 in a centrosymmetric monoclinic unit cell. The molecule contains two planar fragments, viz. the benzene and imidazole rings, linked by two C-C single bonds. The dihedral angle between the two planes is 59.54 (5)° and the molecule adopts a synclinal conformation. The HOMA (harmonic oscillator model of aromaticity) index, calculated for the benzene ring, demonstrates no substantial interaction between the two π-electron delocalization regions in the molecule. In the crystal structure, there is an O-H...N hydrogen bond that links the molecules along the c axis.
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http://dx.doi.org/10.1107/S0108270112007597 | DOI Listing |
Biomed Chromatogr
February 2025
Guangdong Provincial key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, China.
Praziquantel (PZQ) is the most effective treatment for schistosomiasis, commonly administered as a racemic mixture of the two enantiomers. Despite many reports on the pharmacokinetics of PZQ, the stereoselective pharmacokinetics of PZQ and its major metabolite 4-hydroxypraziquantel (4-OH-PZQ) remain poorly understood in goats. In this study, the chiral LC-MS/MS method was further optimized for separating and quantifying PZQ, trans-4-OH-PZQ, and cis-4-OH-PZQ and their enantiomers and then applied for the molecular pharmacokinetics of three analytes in black goat plasma.
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January 2025
Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland.
Building on our previous studies, which have demonstrated that homochiral propagating species-(*,*)-[MeGa(-OCH(Me)COR)]-were crucial for the heteroselectivity of [MeGa(-OCH(Me)COMe)] in the ring-opening polymerization (ROP) of racemic lactide (-LA), we have investigated the effect of alkyl groups on the structure and catalytic properties of dialkylgallium alkoxides in the ROP of -LA. Therefore, we have isolated and characterized the -[RGa(-OCH(Me)COMe] (R = Et (), Pr () and -[RGa(-OCH(Me)CHN] (R = Et (), Pr ()) complexes, to demonstrate the effect of alkyl groups on the chiral recognition induced the formation of the respective homochiaral species-(*,*)-[RGa(-OCH(Me)COMe)] and (*,*)-[RGa(-OCH(Me)CHN]. Moreover, we have investigated the structure of (,)-[RGa(-OCH(Me)COMe] (R = Et ((,)-, R = Pr ((,)-,) and their catalytic activity in the ROP of -LA.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Shanghai Inst Org Chem, State Key Lab Organometallic Chem, 345 Lingling Lu, 200032, Shanghai, CHINA.
Rhodium-catalyzed regio- and enantioselective allylic arylation of racemic alkyl- and aryl- substituted allylic carbonates with arylboronic acids using commercially available BIBOP ligand is reported. This reaction proceeds at room temperature without base or other additive to deliver allylic arylation products in excellent yields, regio- and enantioselectivity (up to 95% yield, >20:1 b/l, >99% ee). Rh/BIBOP is disclosed as an efficient catalytic system for allylic substitution reaction.
View Article and Find Full Text PDFOrg Chem Front
December 2024
Departamento de Química Orgánica I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid Av. Complutense S/N 28040 Madrid Spain
Supramolecular chemistry of carbon-based materials provides a variety of chemical structures with potential applications in materials science and biomedicine. Here, we explore the supramolecular complexation of fullerenes C and C, highlighting the ability of molecular nanographene tweezers to capture these structures. The binding constant for the CNG-1⊃C complex was significantly higher than for CNG-1⊃C, showing a clear selectivity for the more π-extended C.
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December 2024
EaStCHEM School of Chemistry, University of St Andrews, St Andrews, Fife KY16 9ST, United Kingdom.
In the title compound, CHNO the pyrrolidine ring is almost planar and subtends a dihedral angle of 85.77 (7)° with the pendant phenyl ring. An intra-molecular N-H⋯O hydrogen bond generates an (6) loop.
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