Mono-olefins and 1,4-dienes have been synthesised with >99% stereochemical purity by the methylcopper-inducedcross-coupling of dialkenylchloroboranes, formed from alkynes, with organichalides.
The title reaction is found to proceed in the presence of a palladium catalyst and in the absence of any activator. Various functional groups are tolerated to give a diverse range of 1,4-diene and diarylmethane products, which are ubiquitous units of natural products and pharmaceuticals.
Palladium-Catalyzed Asymmetric Allylic C–H Alkylation of 1,4-Dienes with Cyclic β-Keto Esters
作者:Lian-Feng Fan、Tian-Ci Wang、Pu-Sheng Wang、Liu-Zhu Gong
DOI:10.1021/acs.organomet.9b00363
日期:2019.10.28
In the presence of chiral phosphoramidite ligand, a palladium-catalyzed asymmetric allylic C–H alkylation of 1,4-dienes with cyclic β-keto esters has been established to afford chiral α,α-disubstituted β-keto esters in good to excellent yields, with high levels of regioselectivity, E/Z selectivity, and enantioselectivity. 1,4-Dienes bearing a wide scope of functional groups, such as ketone, chloride