Diastereoselective pinacol coupling of alkyl aryl ketones with rare earth metals in the presence of chlorosilanes

✍ Scribed by Akiya Ogawa; Hiroki Takeuchi; Toshikazu Hirao

• Book ID: 104262285
• Publisher: Elsevier Science
• Year: 1999
• Tongue: French
• Weight: 163 KB
• Volume: 40
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(99)01504-x

✦ Synopsis

Rare earth metals (Ln) are found to act as useful reducing agents for the pinacol coupling reaction of alkyl aryl ketones in the presence of chlorosilanes. Although the hitherto known pinacol coupling reaction using rare earth reducing agents generally exhibits very low diastereoselectivities, the present pinacol coupling by use of a Ln/R3SiCI system usually indicates higher diastereoselectivities. In particular, a Yb/Me~SiCl system attains the diastereoselective pinacol coupling of primary alkyl aryl ketones with the dl/meso ratio of 8/2-9/I.