Zinc-Catalyzed Allenylations of Aldehydes and Ketones

详细信息    查看全文

• 作者：Daniel R. Fandrick ; Jaideep Saha ; Keith R. Fandrick ; Sanjit Sanyal ; Junichi Ogikubo ; Heewon Lee ; Frank Roschangar ; Jinhua J. Song ; Chris H. Senanayake
• 刊名：Organic Letters
• 出版年：2011
• 出版时间：October 21, 2011
• 年：2011
• 卷：13
• 期：20
• 页码：5616-5619
• 全文大小：756K
• 年卷期：v.13,no.20(October 21, 2011)
• ISSN：1523-7052

文摘

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 B/Zn 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.