Practical Stereo‐ and Regioselective, Copper(I)‐Promoted <i>Strecker</i> Synthesis of Sugar‐Modified <i>α</i>,<i>β</i>‐Unsaturated Imines

Abstract

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 &gt; 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.