【作者】 冯小明；

【Author】 Xiaoming Feng;College of Chemistry,Sichuan University;

【机构】 四川大学化学学院；

【摘要】 高效高选择性的不对称催化反应是绿色催化的重要研究方向。我们以廉价易得的手性氨基酸为原料,设计合成了一类新型手性双氮氧-酰胺化合物,能与二十多种金属离子络合,形成高效高选择性的金属配合物催化剂,是一类新型"优势"手性配体。1-2三氟甲磺酸钪具有性质稳定,催化活性高,可回收利用等优点。我们利用手性双氮氧-钪配合物实现了多类不对称催化反应。我们将报道利用手性双氮氧-三氟甲磺酸钪配合物催化重氮与羰基化合物之间的系列不对称反应,如Roskamp反应、α-胺化反应、扩环反应等;催化烯酮的卤胺化反应,这些反应的催化剂用量可低至万分之五。该类催化剂还能高效催化烯酮与双氧水间的不对称环氧化反应,体系对水的容忍度强,反应完后手性配体和金属能回收再利用。更多还原

【Abstract】 Asymmetric Catalysis with high efficiency and stereoselectivity is an important research area towards green chemistry. We developed a kind of privileged chiral N,N’-dioxide ligands from readily available amino acids and amines. They can coordinate with a wide variety of metal ions to form chiral metal complex catalysts which enable an intriguing and easily fine-tuned chiral platform for a number of asymmetric reactions. In this report, we will focused on chiral N,N’-dioxide–Sc(OTf)3 complexes catalyzed asymmetric transformation, such as different reactions of α-diazoesters with aldehydes and ketones, asymmetric haloamination of enones. In these cases, high yields and enatioselectivities were achieved with the catalyst loading lower to 0.05 mol%. Chiral N,N′-dioxide–Sc(OTf)3 systems could also act as efficient catalysts for the asymmetric epoxidation of α,β-unsaturated carbonyl compounds using H2O2(0.3%–30% aq.) without additives. Both the ligand and the metal salt could be recycled and reused which proved the efficiency of this kind of catalyst.更多还原