RESUMO
An unprecedented α-allylation of amines was achieved by combining palladium catalysis and visible-light photoredox catalysis. In this dual catalysis process, the catalytic generation of allyl radical from the corresponding π-allylpalladium intermediate was achieved without additional metal reducing reagents (redox-neutral). Various allylation products of amines were obtained in high yields through radical cross-coupling under mild reaction conditions. Moreover, the transformation was applied to the formal synthesis of 8-oxoprotoberberine derivatives which show potential anticancer properties.
RESUMO
A photocatalytic formal [3+2] cycloaddition of 2H-azirines with alkynes has been achieved under irradiation by visible light in the presence of organic dye photocatalysts. This transformation provides efficient access to highly functionalized pyrroles in good yields and has been applied to the synthesis of drug analogues. A primary trial of photocascade catalysis merging energy transfer and redox neutral reactions was shown to be successful.
Assuntos
Luz , Pirróis/química , Alcinos/química , Azirinas/química , Catálise , Corantes/química , Reação de Cicloadição , Transferência de Energia , Inibidores de Hidroximetilglutaril-CoA Redutases/síntese química , Inibidores de Hidroximetilglutaril-CoA Redutases/química , Metais/química , OxirreduçãoRESUMO
A novel method for the synthesis of 1,4-diketones from ß-ketosulfones was developed by means of a visible light-induced C-S bond activation process. Symmetrical and unsymmetrical 1,4-diketones can be easily prepared in moderate to good yields.
Assuntos
Cetonas/química , Compostos de Sulfidrila/química , Sulfonas/química , Catálise , Luz , Estrutura MolecularRESUMO
Sequence catalysis merging photoredox catalysis (PC) and nucleophilic catalysis (NC) has been realized for the direct sp(3) C-H acroleination of N-aryl-tetrahydroisoquinoline (THIQ). The reaction was performed under very mild conditions and afforded products in 50-91% yields. A catalytic asymmetric variant was proved to be successful with moderate enantioselectivities (up to 83 : 17 er).
Assuntos
Aminas/síntese química , Tetra-Hidroisoquinolinas/química , Aminas/química , Catálise , Estrutura Molecular , Oxirredução , Processos Fotoquímicos , EstereoisomerismoRESUMO
All lit up: A novel and efficient desulfonylation method of tosyl amides has been developed by means of visible-light-promoted reductive cleavage of N-S bonds. This method has a broad substrate scope, good functional group tolerance, and excellent yields.