Synthesis of Allenyl Mesylate by a Johnson-Claisen Rearrangement. Preparation of 3-(((tert
-Butyldiphenyl-silyl)oxy)methyl)penta-3,4-dien-1-yl Methanesulfonate
hydrolysis at pH 8 to nearly inert at pH 1, and that the Taft parameter of the orthoester substituent allows an adequate prediction of the reaction kinetics. Moreover, the synthesis of an alkyne-capped cryptand enabled the post-functionalization of orthoester cryptands by Sonogashira and CuAAC “click” reactions. The methylation of the resulting triazole furnished a cryptate that was kinetically inert towards
The base-induced formal [4+3] cycloaddition reaction of C,N-cyclic azomethine imines with aza-ortho-quinone methides, generated in situ, is reported. This protocol provided an efficient method for the synthesis of biologically important 1,2,4-triazepine derivatives, with a wide substrate scope and excellent functional-group tolerance, and it gives moderate to excellent yields under mild conditions
Ammonium Complexes of Orthoester Cryptands Are Inherently Dynamic and Adaptive
作者:Xiang Wang、Oleksandr Shyshov、Marko Hanževački、Christof M. Jäger、Max von Delius
DOI:10.1021/jacs.9b01350
日期:2019.6.5
exploring the interrelationship between kinetic and thermodynamic stability. For instance, as a result of optimal NH4+ binding, complex [NH4+⊂ o-Me2-2.2.1] was found to be thermodynamically stable (negligible intermolecular rearrangements over weeks), whereas computational studies indicate that the compound is far from kinetically stable ( intramolecularrearrangements).
Synthesis and antiproliferative activity of 6-phenylaminopurines
作者:María-Dolores Canela、Sandra Liekens、María-José Camarasa、Eva María Priego、María-Jesús Pérez-Pérez
DOI:10.1016/j.ejmech.2014.09.093
日期:2014.11
A series of novel 6-phenylaminopurines have been efficiently synthesized in 3 steps exploring different groups at positions 2, 8 and 9 of the purine ring and at the exocyclic nitrogen atom at position 6. Among the newly described purines, five compounds showed antiproliferative activity with IC50 values below 10 mu M, the tetrahydroquinoline derivative at position 6 of phenylaminopurine being the most active of the series in the six cell lines tested. Moreover, the compounds induced G(2)/M phase arrest in human cervical carcinoma HeLa cells as reported for tubulin depolymerizing agents. (C) 2014 Elsevier Masson SAS. All rights reserved.