RESUMEN
Chiral 1,6-enynes were prepared via Ir-catalyzed allylic substitutions. Their platinum(II) chloride-catalyzed domino enyne isomerization/Diels-Alder reaction provided stereoselective access to complex heterocycles. Very high diastereoselectivity was induced by a chirality center of the enyne.
RESUMEN
An enantioselective total synthesis of (-)-alpha-kainic acid is described. Key steps are an Ir-catalyzed allylic amination with a propargylic amine to provide an enyne and a diastereoselective intramolecular Pauson-Khand reaction. Subsequent steps involve a Baeyer-Villiger reaction, reduction of the resulting lactone, and direct Jones oxidation of a silyl ether.
Asunto(s)
Ácido Kaínico/química , Ácido Kaínico/síntesis química , Aminación , Catálisis , Hidrogenación , Iridio/química , Estereoisomerismo , Especificidad por SustratoRESUMEN
Combination of enantioselective allylation reactions with a tandem hydroformylation-Fischer indole synthesis sequence as a highly diversity-oriented strategy for the synthesis of tryptamines and homologues was explored. This modular approach allows the substituents at C3 of the indole core, the type of the amine moiety, and the distance of the amine moiety to the indole core in the final synthetic step to be defined. The starting materials required for the hydroformylation step were synthesized via iridium catalyzed enantioselective allylic substitution reactions in high yields and excellent enantioselectivities. The Rh catalyzed hydroformylation step in the presence of phenyl hydrazine, allows the in situ formed aldehyde to be trapped as the hydrazone. Subsequent acid catalyzed indolization furnishes the desired indole structures in moderate to good yields.