RESUMO
Direct access to substituted dihydrochalcones from the easily available starting materials 3-hydroxypropionitrile derivatives and arylboronic acids is described. The procedure involves a multicomponent aryl addition/hydroxyl elimination/reduction Heck approach in the presence of a Pd catalyst with excellent functional group tolerance and a wide range of substrates. In addition, mixed 1,3-diarylation of 3-hydroxypropanenitrile using two arylboronic acids with different electronic properties was also achieved.
Assuntos
Ácidos Borônicos , Paládio , Paládio/química , Estrutura Molecular , Ácidos Borônicos/química , CatáliseRESUMO
A palladium-catalyzed tandem addition/cyclization of 2-(2-aminoaryl)acetonitriles with arylboronic acids has been developed for the first time, achieving a new strategy for direct construction of indole skeletons. This system shows good functional group tolerance and remarkable chemoselectivity. In particular, the halogen (e.g., bromo and iodo) substituents are amenable to further synthetic elaborations thereby broadening the diversity of the products. Preliminary mechanistic experiments indicate that this transformation involves sequential nucleophilic addition followed by an intramolecular cyclization.
RESUMO
A palladium-catalyzed addition of potassium aryltrifluoroborates to aliphatic nitriles has been developed, leading to a wide range of alkyl aryl ketones with moderate to excellent yields. Moreover, several dinitriles (e.g., malononitrile, glutaronitrile, and adiponitrile) were applicable to this process for the construction of 1,3-, 1,5-, or 1,6-dicarbonyl compounds. The scope of the developed approach is successfully explored toward the one-step synthesis of 2-arylbenzo[b]furans via sequential addition and intramolecular annulation reactions. The methodology accepted a wide range of substrates and is applicable to library synthesis.
