Catalytic Enantioselective Construction of All-Carbon Quaternary Stereocenters: Synthetic and Mechanistic Studies of the C-Acylation of Silyl Ketene Acetals
摘要:
With the aid of an appropriate chiral catalyst, acyclic silyl ketene acetals react with anhydrides to furnish 1,3-dicarbonyl compounds that bear all-carbon quaternary stereocenters in good ee and yield. Mechanistic studies provide strong support for a catalytic cycle that involves activation of both the electrophile (anhydride -> acylpyridinium) and the nucleophile (silyl ketene acetal -> enolate).
Catalyst-free, visible-light-promoted S–H insertion reaction between thiols and α-diazoesters
作者:Jingya Yang、Ganggang Wang、Shuwen Chen、Ben Ma、Hongyan Zhou、Menghui Song、Cai Liu、Congde Huo
DOI:10.1039/d0ob02006k
日期:——
A visible-light-promoted S–H insertion reaction betweenthiols and α-diazoesters was developed. The reaction proceeded smoothly at room temperature with a broad substrate scope, affording various thioethers in moderate to excellent yields. The catalyst- and additive-free nature, sustainable energy source and mild reaction conditions make this strategy more eco-friendly.
Catalytic Enantioselective Construction of All-Carbon Quaternary Stereocenters: Synthetic and Mechanistic Studies of the C-Acylation of Silyl Ketene Acetals
作者:Ara H. Mermerian、Gregory C. Fu
DOI:10.1021/ja043832w
日期:2005.4.1
With the aid of an appropriate chiral catalyst, acyclic silyl ketene acetals react with anhydrides to furnish 1,3-dicarbonyl compounds that bear all-carbon quaternary stereocenters in good ee and yield. Mechanistic studies provide strong support for a catalytic cycle that involves activation of both the electrophile (anhydride -> acylpyridinium) and the nucleophile (silyl ketene acetal -> enolate).