RESUMEN
Transition metal-catalysed carbene- and nitrene transfer to the C1-building blocks carbon monoxide and isocyanides provides heteroallenes (i.e. ketenes, isocyanates, ketenimines and carbodiimides). These are versatile and reactive compounds allowing in situ transformation towards numerous functional groups and organic compounds, including heterocycles. Both one-pot and tandem processes have been developed providing valuable synthetic methods for the organic chemistry toolbox. This review discusses all known transition metal-catalysed carbene- and nitrene transfer reactions towards carbon monoxide and isocyanides and in situ transformation of the heteroallenes hereby obtained, with a special focus on the general mechanistic considerations.
Asunto(s)
Cianuros , Elementos de Transición , Monóxido de Carbono/química , Iminas , Metano/análogos & derivados , Metano/químicaRESUMEN
A 3-step methodology for the synthesis of 1,5-benzothiazepin-4(5H)-one dipeptidomimetics has been elaborated via an Ugi-4CR followed by a S-trityl deprotection and an intramolecular Cu(i)-catalyzed Ullmann condensation with moderate to good yields. In silico and NMR conformational studies showed that the lowest energy conformers stabilize γ- and ß-turn structures.
RESUMEN
The antiprotozoal properties of a series of amino substituted 1-methyl-1 H-alpha-carbolines were investigated in a broad panel of parasites. Various substituents were systematically introduced at various positions on the carbocyclic ring of the parent 1-methyl-1 H-alpha-carboline. Most compounds showed a potent antiprotozoal activity, although mostly accompanied by cytotoxicity on MRC-5 cells. One compound, containing the same amino-substitution as chloroquine, showed an IC50 against Plasmodium falciparum of 2.37 microM and was reasonably selective.
Asunto(s)
Antimaláricos/síntesis química , Antimaláricos/farmacología , Antiprotozoarios/síntesis química , Antiprotozoarios/farmacología , Carbolinas/síntesis química , Carbolinas/farmacología , Animales , Línea Celular , Supervivencia Celular/efectos de los fármacos , Humanos , Leishmania infantum/efectos de los fármacos , Plasmodium falciparum/efectos de los fármacos , Relación Estructura-Actividad , Trypanosoma brucei brucei/efectos de los fármacos , Trypanosoma cruzi/efectos de los fármacosRESUMEN
A new method to graft titania with organic groups has been developed. In contrast to common condensation based grafting methods, this method uses organometallic chemistry to bond organic groups directly at the surface. Thereby the introduction of hetero elements at the bonding interface is avoided.