通过TiCl 4(THF)2与衍生自带有大体积苯甲酰基的配体(L1 - L6)的6-烷基-2-铝二氨基酚盐的钾盐的化学计量反应,合成了一系列三氯钛2-铝二氨基苯氧基化物配合物(C1 - C6)取代基,而在配体L6与0.5当量的TiCl 4(THF)2的反应中分离出双(2-二氨基苯氧基)钛二氯化物(C7)。所有钛配合物的特征是1 H / 1313 C NMR光谱和元素分析。单晶X射线衍射揭示了配合物C2,C4和C7的钛中心周围的八面体几何形状失真。经助催化剂MAO活化后,所有钛预催化剂在70°C的乙烯聚合反应中均表现出良好至高的活性(至多1.3×10 6 g mol(Ti)-1 h -1),从而生产出具有高活性的聚乙烯产品。分子量。此外,以10 5 g mol(Ti)-1 h -1的活性实现了乙烯与α-烯烃或降冰片烯的共聚。 通过这些钛预催化剂与共聚单体的良好结合,对于1-己烯通常分别为4
Ytterbium-Catalyzed Hydroboration of Aldehydes and Ketones
作者:Weifan Wang、Xingchao Shen、Fengyi Zhao、Huan Jiang、Weiwei Yao、Sumod A. Pullarkat、Li Xu、Mengtao Ma
DOI:10.1021/acs.joc.7b02076
日期:2018.1.5
efficient catalyst for the hydroboration of a wide range of aldehydes and ketones with pinacolborane (HBpin) at room temperature. The protocol requires low catalyst loadings (0.1–0.5 mol %) and proceeds rapidly (>99% conversion in <10 min). Additionally, catalyst 1 shows a good functional group tolerance even toward the hydroxyl and amino moieties and displays chemoselective hydroboration of aldehydes over
give the unexpected homoleptic magnesiumcomplex 2 (L1MgL1) in good yield. However, the reaction of sterically more bulky ligand 3 (L2H) with CH3MgI in diethyl ether yielded the desired heteroleptic magnesiumiodide 4 [L2MgI(OEt2)], which was further reduced with sodium to produce the Mg–Na heterodimetallic complex 5. The crystal structures of all new magnesiumcomplexes were determined by single-crystal