RESUMO
The use of aryl triflates as reaction partners in a palladium-catalyzed domino direct arylation/N-arylation provides a great advantage due to the availability of starting materials. Furthermore, it allows expedient access to biologically interesting benzo[c]phenanthridine alkaloids.
Assuntos
Alcaloides/síntese química , Benzofenantridinas/síntese química , Mesilatos/química , Paládio/química , Alcaloides/química , Benzofenantridinas/química , Catálise , Técnicas de Química Combinatória , Estrutura MolecularAssuntos
Alcinos/química , Amidas/síntese química , Rutênio/química , Amidas/química , Catálise , EstereoisomerismoRESUMO
A catalyst system generated in situ from bis(2-methallyl)-cycloocta-1,5-diene-ruthenium(II) and a phosphine was found to efficiently catalyze the addition of thioamides to terminal alkynes with exclusive formation of the anti-Markovnikov thioenamide products. The stereoselectivity of the addition is usually high and controlled by the choice of the phosphine ligand, whereas the (E)-isomers are predominantly formed in the presence of tri(n-octyl)phosphine, the use of bis(dicyclohexylphosphino)methane preferentially leads to the formation of the (Z)-configured thioenamides.
Assuntos
Alcinos/síntese química , Rutênio/química , Tioamidas/química , Alcinos/química , Catálise , Estrutura Molecular , Estereoisomerismo , Compostos de Sulfidrila/químicaRESUMO
A catalyst system formed in situ from bis(2-methylallyl)cycloocta-1,5-dieneruthenium(II) ((cod)Ru[met]2), a phosphine, and scandium(III) trifluoromethanesulfonate (Sc(OTf)3) was found to efficiently catalyze the anti-Markovnikov addition of imides to terminal alkynes, allowing mild and atom-economic synthesis of enimides. Depending on the phosphine employed, both the (E)- and the (Z)-isomer can be accessed stereoselectively.
