Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu, China.
Org Biomol Chem. 2011 Aug 21;9(16):5748-54. doi: 10.1039/c1ob05558e. Epub 2011 Jun 30.
A highly efficient catalytic asymmetric vinylogous Mukaiyama-Michael reaction of the 2-silyloxyfuran with chalcone derivatives, catalyzed by a chiral N,N'-dioxide-scandium(III) complex, has been accomplished which tolerates a wide range of substrates. The reaction proceeds with complete regioselectivities, excellent diastereoselectivities (up to >99 : 1 dr) and good to excellent enantioselectivities (up to 94% ee) under mild conditions, delivering highly functionalized enantiomerically enriched anti-γ-substituted butenolides. The process is air-tolerant and easily manipulated with available reagents. In order to illustrate the synthetic potential of this reaction, the gram-scale synthesis and the elaboration of the butenolides have been explored. On the basis of the experimental results, a possible catalytic cycle and favorable stereorecognition model have been proposed.
一种高效的催化不对称乙烯基 Mukaiyama-Michael 反应，在手性 N，N'-二氧化物-钪（III）配合物的催化下，完成了 2-硅氧基呋喃与查耳酮衍生物的反应，该反应可以容忍广泛的底物。该反应在温和条件下具有完全的区域选择性、优异的非对映选择性（高达 >99:1 dr）和良好到优异的对映选择性（高达 94%ee），得到了高度官能化的对映体富集的反-γ-取代丁烯内酯。该过程对空气具有耐受性，并且可以使用现有的试剂轻松操作。为了说明该反应的合成潜力，已经探索了该反应的克级合成和丁烯内酯的衍生化。根据实验结果，提出了一个可能的催化循环和有利的立体识别模型。
