作者:Mike Boysen、Holger Grugel、Tobias Minuth
DOI:10.1055/s-0030-1258190
日期:2010.10
olefin-phosphinite hybrid ligands has been designed. These ligands were prepared by attaching phosphinite or allylic donor sites onto unsaturated carbohydrate scaffolds. In rhodium(I)-catalysed conjugate addition of boronic acids to enones, the olefin-phosphinite hybrids gave products in up to 99% ee and above, whereas the dienes only led to modest enantioselectivity. However, by shifting the allylic donor
从容易获得的单糖d-葡萄糖和d-阿拉伯糖开始,已经设计了一系列新的手性二烯和烯烃-次膦酸酯杂化配体。通过将次膦酸酯或烯丙基供体位点连接到不饱和碳水化合物支架上来制备这些配体。在铑(I)催化的硼酸向烯酮的共轭加成中,烯烃-次亚膦酸酯杂化物的收率高达99%ee或更高,而二烯仅导致中等的对映选择性。然而,通过将烯丙基供体位点从吡喃糖的4位转移到异头中心,观察到了立体诱导过程的意外逆转。 碳水化合物-配体设计-不对称催化-铑-硼