The chiral scandium(III) triflate/i-Pr-pybox complex efficiently catalyzes the asymmetric Diels-Alder reaction of 1,3-dienes with acyl-1,3-oxazolidin-2-ones (1 a - c) afford the corresponding adducts in good yields with up to 90% ee. The reaction can be carried out in less toxic benzotrifluoride and supercritical carbon dioxide while remaining good selectivity (65-75% ee).
手性
钪(III)三late/i-Pr-pybox 复合物可高效催化 1,3-二烯与酰基-1,3-
噁唑烷-2-酮(1 a - c)的不对称 Diels-Alder 反应,以高产率和高达 90% 的 ee 生成相应的加合物。该反应可在毒性较低的
三氟甲苯和超临界
二氧化碳中进行,同时保持良好的选择性(65-75% ee)。