Asymmetric phase transfer Darzens reactions catalyzed by d-glucose- and d-mannose-based chiral crown ethers
作者:Zsolt Rapi、Péter Bakó、György Keglevich、Áron Szöllősy、László Drahos、Adrienn Botyánszki、Tamás Holczbauer
DOI:10.1016/j.tetasy.2012.04.006
日期:2012.4
and d-mannose-based crown ethers 1 and 2 as the catalyst. The use of d-glucose-based lariat ether 1 as the catalyst gave the best results. The reaction of 4-phenyl-α-chloroacetophenone, 2-chloro-1-tetralone, and 2-chloro-1-indanone with various aromatic aldehydes afforded the corresponding aromatic α,β-epoxyketones in moderate to high enantiomeric excess (ee up to 96%) under mild reaction conditions
液相-液相不对称Darzens缩合反应是在基于d-葡萄糖和d-甘露糖的冠醚1和2的存在下进行的。使用基于d-葡萄糖的套索状醚1作为催化剂可获得最佳结果。4-苯基-α-氯乙酰苯酮,2-氯-1-四氢萘酮和2-氯-1-茚满酮与各种芳族醛的反应可得到相应的芳族α,β-环氧酮,其对映体过量至中度对映体过量(ee最高可达96%)在温和的反应条件下。用作反应物的苯甲醛的取代基对化学收率和对映体过量有重大影响。一些环氧酮产品的绝对构型是通过单晶X射线分析确定的。