RESUMEN
The first Suzuki-Miyaura cross-coupling reactions of the synthetically versatile aryl O-carbamate and O-sulfamate groups are described. The transformations utilize the inexpensive, bench-stable catalyst NiCl(2)(PCy(3))(2) to furnish biaryls in good to excellent yields. A broad scope for this methodology has been demonstrated. Substrates with electron-donating and electron-withdrawing groups are tolerated, in addition to those that possess ortho substituents. Furthermore, heteroaryl substrates may be employed as coupling partners. A computational study providing the full catalytic cycles for these cross-coupling reactions is described. The oxidative addition with carbamates or sulfamates occurs via a five-centered transition state, resulting in the exclusive cleavage of the aryl C-O bond. Water is found to stabilize the Ni-carbamate catalyst resting state, which thus provides rationalization of the relative decreased rate of coupling of carbamates. Several synthetic applications are presented to showcase the utility of the methodology in the synthesis of polysubstituted aromatic compounds of natural product and bioactive molecule interest.
Asunto(s)
Carbamatos/química , Ácidos Sulfónicos/químicaAsunto(s)
Insuficiencia Cardíaca , Hospitalización , Humanos , Insuficiencia Cardíaca/tratamiento farmacológico , Insuficiencia Cardíaca/fisiopatología , Masculino , Femenino , Anciano , Persona de Mediana Edad , Estudios Retrospectivos , Proyectos Piloto , Adulto , Volumen Sistólico/efectos de los fármacos , Péptido Natriurético Encefálico/sangreAsunto(s)
Insuficiencia Cardíaca , Volumen Sistólico , Humanos , Insuficiencia Cardíaca/tratamiento farmacológico , Insuficiencia Cardíaca/fisiopatología , Insuficiencia Cardíaca/mortalidad , Masculino , Hungría , Femenino , Estudios Retrospectivos , Pronóstico , Volumen Sistólico/efectos de los fármacos , Persona de Mediana Edad , Anciano , Inhibidores del Cotransportador de Sodio-Glucosa 2/uso terapéutico , Antagonistas Adrenérgicos beta/uso terapéutico , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéuticoRESUMEN
Palladium on charcoal serves as an efficient and reusable solid supported catalyst for the Sonogashira coupling of aryl chlorides with terminal acetylenes in the presence of a bulky, electron-rich biphenyl type ligand (XPhos), without copper co-catalyst.