Asymmetric Construction of Quaternary Stereocenters by Direct Organocatalytic Amination of -Substituted <img src="http://pubs.acs.or
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- 作者：Steen Saaby ; Marco Bella ; and Karl Anker J<img src="http ; //pubs.acs.org/images/gifchars/oslash.gif" border="0">rgensen
- 刊名：Journal of the American Chemical Society
- 出版年：2004
- 出版时间：July 7, 2004
- 年：2004
- 卷：126
- 期：26
- 页码：8120 - 8121
- 全文大小：52K
- 年卷期：v.126,no.26(July 7, 2004)
- ISSN：1520-5126
文摘
The first organocatalytic highly enantioselective reactions of substituted <IMG SRC="/images/gifchars/alpha.gif" BORDER=0>-cyanoacetates and 
-dicarbonyl compounds with azodicarboxylates are reported. In the presence of 0.1-5 mol % of a quinidine-derived alkaloid -ICD, optically active quaternary hydrazine adducts are obtained in very high yields and with enantioselectivities up to >98% ee. A two-step procedure for the cleavage of the hydrazine N-N bond using SmI2 is also demonstrated.
-dicarbonyl compounds with azodicarboxylates are reported. In the presence of 0.1-5 mol % of a quinidine-derived alkaloid -ICD, optically active quaternary hydrazine adducts are obtained in very high yields and with enantioselectivities up to >98% ee. A two-step procedure for the cleavage of the hydrazine N-N bond using SmI2 is also demonstrated.