Tris(trimethylsilyl)silyl-Governed Aldehyde Cross-Aldol Cascade Reaction
详细信息 查看全文
- 作者：Matthew B. Boxer and Hisashi Yamamoto
- 刊名：Journal of the American Chemical Society
- 出版年：2006
- 出版时间：January 11, 2006
- 年：2006
- 卷：128
- 期：1
- 页码：48 - 49
- 全文大小：65K
- 年卷期：v.128,no.1(January 11, 2006)
- ISSN：1520-5126
文摘
The use of the tris(trimethylsilyl)silyl (TTMSS) group in aldehyde-derived silyl enol ethers affords aldehyde cross-aldol products with high yields and allows for unprecedented reactivity. The reaction is catalyzed by 0.05 mol % of HNTf2, and can easily be managed to give 
,
-bis-, ,,
-tris-, and ,,
-tris-hydroxy-aldehydes with extremely high selectivity by simple stoichiometric control. High diastereoselectivity is obtained in all cases, and the use of chiral aldehydes affords Felkin products when there are nonchelating substituents, chelation products when there is a chelating sbustituent, and syn products when there is -substitution. HNTf2 is proposed to be an initiator, and highly Lewis acidic TTMSSNTf2 is the true catalyst.
,-bis-, ,,-tris-, and ,,-tris-hydroxy-aldehydes with extremely high selectivity by simple stoichiometric control. High diastereoselectivity is obtained in all cases, and the use of chiral aldehydes affords Felkin products when there are nonchelating substituents, chelation products when there is a chelating sbustituent, and syn products when there is -substitution. HNTf2 is proposed to be an initiator, and highly Lewis acidic TTMSSNTf2 is the true catalyst.