Zinc-Salen-Catalyzed Asymmetric Alkynylation of Alkyl Acylsilanes

✍ Scribed by Feng-Quan Li; Shi Zhong; Gui Lu; Albert S. C. Chan

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 185 KB
• Volume: 351
• Category: Article
• ISSN: 1615-4150
• DOI: 10.1002/adsc.200900177

✦ Synopsis

Abstract

Optically active tertiary propargylic alcohols are useful and versatile building blocks in organic synthesis, and their direct access by enantioselective addition of alkyne nucleophiles to ketones has achieved significant progress over the last ten years. In view of the potential applications of acylsilanes as useful synthetic equivalents of aldehydes, we described a general catalytic enantioselective addition of terminal alkynes to alkyl acylsilanes. After reaction optimization involving variation of solvent, temperature, catalyst ratio and various catalysts screen, the in situ generated Zn‐salen complex was chosen as catalyst. With hexane as solvent, the silylated tertiary propargylic alcohols were obtained in satisfactory yields and __ee__s for both aliphatic and aromatic alkynes.