Chromium(II)-catalyzed diastereoselective pinacol type cross coupling: studies of substrate-controlled effects

✍ Scribed by Ulrich Groth; Marc Jung; Steffen Lang; Thilo Schuppler

• Publisher: Elsevier Science
• Year: 2009
• Tongue: French
• Weight: 167 KB
• Volume: 50
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/j.tetlet.2008.10.117

✦ Synopsis

Using 20 mol % of CrCl 2 as catalyst, manganese powder as reducing agent, and TMS-Cl as scavenger, various acroleins and aldehydes were coupled with moderate to high yields and diastereomeric excesses. Alkyl aldehydes usually favor syn configuration while aldehydes with functional groups containing chelating hetero atoms promote the formation of anti configuration. Using sterically demanding alkyl residues on the acrolein substrate, the syn configuration is definitely preferred.