RESUMEN
The first total syntheses of two marine natural products, (R)-strongylodiols C and D, with 99% ee were achieved. The key steps of the strategy include the zipper reaction of an alkyne, the asymmetric alkynylation of an unsaturated aliphatic aldehyde catalyzed with Trost's ProPhenol ligand, and the Cadiot-Chodkiewicz cross-coupling reaction of a chiral propargylic alcohol with a bromoalkyne.
Asunto(s)
Alcoholes/síntesis química , Alquinos/síntesis química , Productos Biológicos/síntesis química , Alcoholes/química , Alquinos/química , Productos Biológicos/química , Catálisis , Ligandos , Estructura Molecular , Propanoles/química , EstereoisomerismoRESUMEN
The first catalytic asymmetric Kumada cross-coupling of organic halides with alkenyl Grignard reagents has been developed. The reaction was promoted by the cobalt-bisoxazoline catalyst and afforded various α-alkyl-ß,γ-unsaturated esters with excellent enantioselectivities and moderate to good yields (≤95% ee and ≤82% yields). The formal synthesis of the California red scale pheromone using this method was investigated, and radical clock experiments were performed.