由手性膦BINAP容易制备的手性膦氧化物BINAPO在三氯甲硅烷基化合物通过高价硅酸盐中间体的反应中表现出良好的催化活性。在催化量的BINAPO存在下,醛与烯丙基三氯硅烷的烯丙基化反应使烯丙基化的加合物具有良好的对映选择性(最高79%ee),其中二异丙基乙胺和四丁基碘化铵作为添加剂的组合对于加速催化循环至关重要。31氧化膦的1 P NMR分析表明,胺促进了氧化膦从硅原子上的解离。BINAPO还促进了二异丙基乙胺作为添加剂存在下醛与三氯甲硅烷基烯醇醚的对映体选择性醛醇缩合反应,从而以高非对映体和对映体选择性(最高syn / anti = 1 / 25,96%ee(anti))提供了相应的醛醇加合物。)。
active homoallylic alcohols from allylhalides was developed. Allyltrichlorosilanes were generated in situ from allylhalides and trichlorosilane in the presence of cuprous chloride and tertiary amine. Without isolation of the allyltrichlorosilanes, benzaldehyde and chiral biquinoline N,N'-dioxide were introduced into the same flask, producing the corresponding homoallylic alcohols with good to high
The effectiveness of chiral phosphine oxide BINAPO as a catalyst for the enantioselective addition of allyltrichlorosilanes to aldehydes was demonstrated, wherein the combination of diisopropylethylamine and tetrabutylammonium iodide as additives is crucial for accelerating the catalytic cycle.
Atropisomeric Chiral Dienes in Asymmetric Catalysis:<i>C</i><sub>2</sub>-Symmetric (<i>Z</i>,<i>Z</i>)-2,3-Bis[1-(diphenylphosphinyl)ethylidene]tetralin as a Highly Active Lewis Base Organocatalyst
Diene catalysts with a twist: The title C2‐symmetric tetralin‐fused 1,3‐butadiene derivative is atropisomeric and can be resolved into the two helical enantiomers. The optically pure compound showed excellent enantioselectivity as well as unusually high catalytic activity as a chiralLewis basic organocatalyst in the asymmetric allylation of various aldehydes with β‐substituted allyltrichlorosilanes