Zinc-Catalyzed Allenylations of Aldehydes and Ketones
摘要:
The general zinc-catalyzed allenylation of aldehydes and ketones with an allenyl boronate Is presented. Preliminary mechanistic studies support a kinetically controlled process wherein, after a site-selective Ban exchange to generate a propargyl zinc intermediate, the addition to the electrophile effectively competes with propargyl-allenyl zinc equilibration. The utility of the methodology was demonstrated by application to a rhodium-catalyzed [4 + 2] cycloaddition.
3,4-Alkadienyl ketones via the palladium-catalyzed decarboxylative allenylation of 3-oxocarboxylic acids
作者:Tonghao Zhu、Shengming Ma
DOI:10.1039/c7cc02050c
日期:——
In this communication, we report a palladium-catalyzed decarboxylative allenylation of benzyl carbonates and tert-butyl carbonates of 2,3-allenols with 3-oxocarboxylic acids. The reaction provides a new and straightforward approach to 3,4-dienyl ketones under mild conditions.