Helicene-Based Phosphite Ligands in Asymmetric Transition-Metal Catalysis: Exploring Rh-Catalyzed Hydroformylation and Ir-Catalyzed Allylic Amination
作者:Zuzana Krausová、Petr Sehnal、Bojan P. Bondzic、Serghei Chercheja、Peter Eilbracht、Irena G. Stará、David Šaman、Ivo Starý
DOI:10.1002/ejoc.201100259
日期:2011.7
2-dioxaphospholan-2-yl fragment was most effective in asymmetric allylic aminations, exhibiting high enantioselectivity (up to 94 % ee), excellent regioselectivity in favor of the branched products, and good reactivity. This study represents the first use of helicene-like ligands in asymmetric reactions, including hydroformylation and allylic amination, and the promising results indicate the potential of the helicene
从光学纯的 [6] 类螺旋醇 (P,3S)-3-methyl-4-(4-methylphenyl)-1,3,6,7-tetrahydrobenzo[c]benzo[5,6]phenanthro[ 4,3-e]oxepin-14-ol,四个螺旋亚磷酸酯由相应的氯亚磷酸酯制备。这些含有母体或取代的 1,3,2-二氧杂膦基-2-基或二苯并[d,f][1,3,2]二氧膦-6-基部分的配体被应用于由 Rh( acac)(CO)2 和 [Ir(cod)Cl]2 催化肉桂基型碳酸酯的不对称烯丙基胺化。含有二苯并[d,f][1,3,2]dioxaphosphepin-6-yl 基团的螺旋亚磷酸酯在苯乙烯的不对称加氢甲酰化中最为成功,导致适度的对映体过量值(高达 32% ee),高区域选择性有利于支链产品,并且大多是高转化率,而含有 4,4,5,5-tetramethyl-1,3,2-dioxaphospholan-2-yl