Novel and stereoselective methods for the preparation of aromatic lactams via reductive coupling reactions mediated by SmI2

被引:38
作者
Yoda, H [1 ]
Matsuda, K [1 ]
Nomura, H [1 ]
Takabe, K [1 ]
机构
[1] Shizuoka Univ, Fac Engn, Dept Mol Sci, Hamamatsu, Shizuoka 4328561, Japan
基金
日本学术振兴会;
关键词
cross-coupling reaction; samarium(II) diiodide; cyclic imide; stereoselective reduction; deoxygenation;
D O I
10.1016/S0040-4039(00)00014-9
中图分类号
O62 [有机化学];
学科分类号
070303 ; 081704 ;
摘要
Samarium(II) diiodide-mediated reductive cross-coupling of N-alkylated phthalimides with carbonyl compounds is shown to afford hydroxylated alpha-hydroxylactams, Ketoamides obtained by dehydration of these compounds through keto-enol tautomer isomerization were reduced with NaBH4 in a completely stereoselective manner in the presence of CeCl3 to give three-aromatic lactams as the sole product. Direct reductive deoxygenation of these alpha-hydroxylactam intermediates with Et3SiH in the presence of Lewis acid also displayed high stereoselectivity to afford the same threo-lactams exclusively. The mechanistic origins of this stereoselectivity are briefly documented. (C) 2000 Elsevier Science Ltd. All rights reserved.
引用
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页码:1775 / 1779
页数:5
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