Asymmetric Catalysis on the Intramolecular Cyclopropanation of -Diazo-
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- 作者：Masahiro Honma ; Takashi Sawada ; Yuri Fujisawa ; Masayuki Utsugi ; Hideaki Watanabe ; Akinori Umino ; Takehiko Matsumura ; Takayuki Hagihara ; Masashi Takano ; and Masahisa Nakada
- 刊名：Journal of the American Chemical Society
- 出版年：2003
- 出版时间：March 12, 2003
- 年：2003
- 卷：125
- 期：10
- 页码：2860 - 2861
- 全文大小：57K
- 年卷期：v.125,no.10(March 12, 2003)
- ISSN：1520-5126
文摘
This work describes the development of a highly enantioselective asymmetric catalysis on the intramolecular cyclopropanation of 
-diazo-
-keto sulfones. We have found that the catalytic asymmetric intramolecular reactions of -diazo--keto sulfones generally proceed with high enantioselectivity when the -diazo--keto mesityl sulfone is used with the newly prepared ligand 2e. The absolute configuration of products has been determined by X-ray crystallographic analysis, and the outcome of the enantioselectivities is explained well by our proposed models A and B. The products possess great potential for natural product synthesis because (1) many different chemistries of cyclopropane, ketone, and sulfone are available, and (2) the products are generally highly crystalline, facilitating the supplies of enantiomerically pure synthetic intermediates.
-diazo--keto sulfones. We have found that the catalytic asymmetric intramolecular reactions of -diazo--keto sulfones generally proceed with high enantioselectivity when the -diazo--keto mesityl sulfone is used with the newly prepared ligand 2e. The absolute configuration of products has been determined by X-ray crystallographic analysis, and the outcome of the enantioselectivities is explained well by our proposed models A and B. The products possess great potential for natural product synthesis because (1) many different chemistries of cyclopropane, ketone, and sulfone are available, and (2) the products are generally highly crystalline, facilitating the supplies of enantiomerically pure synthetic intermediates.