Influence of secondary ligand on structures and topologies of lanthanide coordination polymers with 1,3,5-triazine-2,4,6-triamine hexaacetic acid

© 2015 Taylor and Francis. A series of new lanthanide coordination polymers has been synthesized and structurally characterized; [Ln 4 (TTHA) 2 (pzac)(H 3 O) 2 (H 2 O)]·5H 2 O (Ln = Pr (1a) and Nd (1b)), [Sm 8 (TTHA) 4 (pzac) 0.5 (H 3 O)(H 2 O) 7.5 ]·4H 2 O (2), [Ln 4 (HTTHA) 2 (SO 4 )(H 2 O) 4 ]·5H 2 O (Ln = Pr (3a) and Nd (3b)), where H 6 TTHA = 1,3,5-triazine-2,4,6-triamine hexaacetic acid, and H 2 pzac = 2,5-dioxo-piperazine-1,4-diacetic acid. The compounds feature 3-D frameworks comprising the deprotonated H 6 TTHA as the primary ligand and either the in situ generated pzac 2- or sulfate as the secondary ligands. The influence of the deprotonated H 6 TTHA in directing the framework structures through preferential coordination modes and molecular conformation is described. The effect of the secondary ligands in increasing the compactness of the frameworks and in the alternation of the framework topologies based on the four-connected pts type is described

Ph₃P/I₂‑Mediated Synthesis of <i>N,N</i>′<i>,N</i>″‑Substituted Guanidines and 2‑Iminoimidazolin-4-ones from Aryl Isothiocyanates

A convenient one-pot procedure for the synthesis of acyclic and cyclic guanidines mediated by the Ph₃P/I₂ system is described. Sequential condensation of aryl isothiocyanates with amines followed by dehydrosulfurization and guanylation could lead to both symmetric and unsymmetric <i>N,N</i>′<i>,N</i>″-substituted derivatives. Through a tandem guanylation–cyclization, a series of 2-iminoimidazolin-4-ones could also be prepared in good yields from the reaction of aryl isothiocyanates with amino acid methyl esters

Application of <i>N</i>‑Acylbenzotriazoles in the Synthesis of 5‑Substituted 2‑Ethoxy-1,3,4-oxadiazoles as Building Blocks toward 3,5-Disubstituted 1,3,4-Oxadiazol-2(3<i>H</i>)‑ones

5-Substituted-2-ethoxy-1,3,4-oxadiazoles were conveniently prepared through a one-pot sequential <i>N</i>-acylation/dehydrative cyclization between ethyl carbazate and <i>N</i>-acylbenzotriazoles in the presence of Ph₃P–I₂ as a dehydrating agent. Subsequent treatment with a stoichiometric amount of alkyl halides (X = Cl, Br, I) enables a rapid access to a variety of 3,5-disubstituted 1,3,4-oxadiazol-2­(3<i>H</i>)-ones in good to excellent yields

Approach to the Synthesis of 2,3-Disubstituted‑3<i>H</i>‑quinazolin-4-ones Mediated by Ph₃P–I₂

Readily available <i>N</i>-substituted amides or their requisite carboxylic acids or acid chlorides have been used to construct 2,3-disubstituted-3<i>H</i>-quinazolin-4-ones in a one-pot procedure. Key transformation in this convergent approach involves Ph₃P–I₂-mediated formation of amidine upon condensation of an amide or the intermediate amide with methyl anthranilate. Cyclization of the amidine-tethered anthranilate then affords 2,3-disubstituted-3<i>H</i>-quinazolin-4-ones in good to excellent yields under mild conditions

Highly diastereoselective synthesis of enantioenriched anti-α-allyl-β-fluoroamines

A highly diastereoselective synthesis ofanti-a-allyl-b-fluoroamineshas been developed involving enantioselectivea-fluorination ofaldehydes followed by a diastereoselective Petasis allyl borono-Mannich reaction. The products are obtained generally in goodoverall yields for the two steps and with drs of 97 : 3-99 : 1 and eesof 86-92%. Selected products were converted to 3-, 5- and6-membered ring heterocycles, the latter two types incorporatingan exo-cyclic fluorine

Immunochromatographic Strip Test for Rapid Detection of Nevirapine in Plasma Samples from Human Immunodeficiency Virus-Infected Patients▿

We report a novel one-step immunochromatographic strip test for the rapid, qualitative detection of nevirapine in plasma samples from human immunodeficiency virus-infected patients. The sensitivity was 100% (95% confidence interval [95% CI], 97.8 to 100%), and the specificity was 99.5% (95% CI, 97.2 to 99.9%). The limit of detection was 25 ng/ml. Immunochromatographic strip tests are simple, rapid, and cheap assays that could greatly facilitate drug level monitoring in resource-limited settings

Ultrasound-Assisted Solvent-Free Parallel Synthesis of 3‑Arylcoumarins Using <i>N</i>‑Acylbenzotriazoles

An ultrasound-assisted one-pot acylation/cyclization reaction between <i>N</i>-acylbenzotriazoles and 2-hydroxybenzaldehydes has been developed for the synthesis of substituted 3-arylcoumarins. Using ultrasound not only allows rapid and clean conversion but also simplifies experimental setup and parallel workup leading to rapid generation of 3-arylcoumarin libraries under mild, solvent-free, and chromatography-free conditions