Diastereoselective atom transfer radical cyclization reactions of unsaturated α-bromo oxazolidinone imides catalyzed by Lewis acids

Dan Yang, Bao Fu Zheng, Shen Gu, Philip W.H. Chan, Nian Yong Zhu

Research output: Contribution to journalArticleResearchpeer-review

11 Citations (Scopus)

Abstract

A new Lewis acid-catalyzed atom transfer radical cyclization reaction of unsaturated α-bromo oxazolidinone imides is reported. In the presence of Lewis acids such as Mg(ClO4)2 and Yb(OTf)3, a series of trans cyclic products was obtained in high yield (up to 87%) between 0°C and room temperature. The loading of strong Lewis acids, such as Yb(OTf)3, can be reduced to 0.1 equiv. without significantly compromising the yield. Excellent diastereoselectivity could be achieved by using 1,2-stereocontrol or a chiral oxazolidinone auxiliary. For substrates 1e and 1f bearing a β-methyl substituent and the chiral auxiliary, (S)-(-)-4-benzyl-5,5-dimethyl-2-oxazolidinone, respectively, the diastereomeric ratio of the products was greater than 50:1.

Original languageEnglish
Pages (from-to)2927-2937
Number of pages11
JournalTetrahedron Asymmetry
Volume14
Issue number19
DOIs
Publication statusPublished - 3 Oct 2003
Externally publishedYes

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