Practical Stereo- and Regioselective, Copper(I)-Promoted Strecker Synthesis of Sugar-Modified α,β-Unsaturated Imines

✍ Scribed by Guobin Zhou; Weixin Zheng; Dong Wang; Pengfei Zhang; Yuanjiang Pan

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: German
• Weight: 94 KB
• Volume: 89
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.200690054

✦ Synopsis

Abstract

The regio‐ and stereoselective, Lewis acid catalyzed Strecker reaction between Me~3~SiCN and different aldimines incorporating a 2,3,4,6‐tetrakis‐O‐pivaloyl‐D‐glucopyranosyl (Piv~4~Glc) chiral auxiliary has been worked out. Depending on the conditions used, high yields (up to 95%) and good diastereoselectivities (de > 86%) were achieved under mild conditions (Table 1), especially with CuBr ⋅ Me~2~S as catalyst. Our protocol allows the ready preparation of asymmetric β,γ‐unsaturated α‐amino acids such as (R)‐2‐amino‐4‐phenylbut‐3‐enoic acid (13; Scheme 2) and congeners thereof.