RESUMO
An efficient synthesis of tryptamines is developed. Indole structures were constructed using 2-iodoaryl allenyl amines as electron acceptors and radical cyclization precursors. Radical-radical coupling of indolyl methyl radicals and azaallyl radicals led to the tryptamine derivatives. The utility and versatility of this method are showcased by the synthesis of 22 examples of tryptamines in ≤88% yield. In each case, indole formation is accompanied by in situ removal of the Boc protecting group.
Assuntos
Aminas , Triptaminas , Ciclização , Indóis/química , Triptaminas/químicaRESUMO
A novel strategy for the synthesis of policyclic trifluoromethyl arenes has been devised. It involves a DBU-promoted tandem cycloaromatization reaction of dicyanoalkenes and fluorinated conjugated sulfinyl imines. This unprecedented transformation is a metal-free and air-tolerant process that takes place from readily available starting materials under mild reaction conditions.
RESUMO
A gold-catalyzed Povarov-type reaction of fluorinated imino esters and furans is described. The process, which takes place in dichoromethane at room temperature, gives rise to novel fluorinated tetrahydrofuran-fused tetrahydroquinolines in good yields and moderate levels of diastereoselectivity in a very simple manner. The reported examples expand the versatility of the Povarov reaction to unprecedented fluorinated substrates, generating scaffolds that contain quaternary α-amino acid units.
RESUMO
The activity of HBF4 (aqueous solution) as a catalyst in propargylation reactions is presented. Diverse types of nucleophiles were employed in order to form new C-O, C-N and C-C bonds in technical acetone and in air. Good to excellent yields and good chemoselectivities were obtained using low acid loading (typically 1 mol-%) under simple reaction conditions.