Highly enantioselective catalytic asymmetric Claisen rearrangement of 2-alkoxycarbonyl-substituted allyl vinyl ethers
作者:Lars Abraham、Marleen Körner、Martin Hiersemann
DOI:10.1016/j.tetlet.2004.03.047
日期:2004.4
Progress in the catalytic asymmetric Claisen rearrangement of 2-alkoxycarbonyl-substituted allyl vinyl ether is reported. Application of a more Lewis acidic catalyst, [Cu(S,S)-t-Bu-box}](H2O)2(SbF6)2, afforded β-chiral α-keto ester with an enantiomeric excess up to 99%. We suggest a highly polarized transition state for the Lewis acid-catalyzed Claisen rearrangement in order to explain the experimental results
报道了2-烷氧基羰基取代的烯丙基乙烯基醚的催化不对称克莱森重排的进展。应用一种更路易斯的酸性催化剂,[Cu (S,S)-t -Bu-box}](H 2 O)2(SbF 6)2,得到对映体过量至99%。我们建议路易斯酸催化的克莱森重排的高极化过渡态,以解释实验结果。