4-Aminothiourea Prolinol tert-Butyldiphenylsilyl Ether: A Chiral Secondary Amine-Thiourea as Organocatalyst for Enantioselective anti-Mannich Reactions

✍ Scribed by Hui Zhang; Yongming Chuan; Zhengyu Li; Yungui Peng

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 210 KB
• Volume: 351
• Category: Article
• ISSN: 1615-4150
• DOI: 10.1002/adsc.200900399

✦ Synopsis

Abstract

anti‐Selective Mannich reactions of N‐p‐methoxyphenyl (PMP)‐protected α‐iminoglyoxylate with unmodified aldehydes or ketones were effectively catalyzed by 4‐aminothiourea prolinol tert‐butyldiphenylsilyl ether. The reactions led to chiral β‐amino carbonyl compounds in high yields (up to 94%), excellent diastereo‐ and enantioselectivities (up to 98% de and >99% ee). The study demonstrated for the first time that direct Mannich‐type reactions of unmodified aldehydes or ketones to α‐iminoglyoxylate can be promoted by secondary amine‐thiourea chiral organocatalyst.