使用乙酰丙酮铁(III)作为前体,在露天条件下合成了高度活化的,单分散的N,N-二甲基甲酰胺(DMF)稳定化的氧化铁纳米颗粒(Fe 2 O 3 NPs)。生成的Fe 2 O 3 NPs通过多种技术进行了表征(例如,透射电子显微镜,动态光散射,X射线衍射,X射线光电子能谱,FTIR光谱和X射线吸附近边缘结构)。铁2 O 3NP对烯烃的氢化硅烷化表现出有效的催化活性,而无需其他添加剂。通过用己烷/ DMF系统萃取,开发了有效的胶体催化剂的再循环方法,并且在五个循环中催化剂的再循环没有导致催化活性的任何显着损失。
Bench-Stable Cobalt Pre-Catalysts for Mild Hydrosilative Reduction of Tertiary Amides to Amines and Beyond
作者:Alibek Nurseiit、Jaysan Janabel、Kristina A. Gudun、Aishabibi Kassymbek、Medet Segizbayev、Tulegen M. Seilkhanov、Andrey Y. Khalimon
DOI:10.1002/cctc.201801605
日期:2019.1.23
unsaturated organic molecules, including the normally challenging reduction of amides to amines. With regard to hydrosilative reduction of amides even more effective and activator free catalytic systems can be generated from the bench‐stable, commercially available Co(acac)2 and Co(OAc)2 with dpephos and PPh3 ligands. These systems operate under mild conditions (<100 °C), with many examples of room temperature
Cobalt-Catalyzed Regiodivergent Hydrosilylation of Vinylarenes and Aliphatic Alkenes: Ligand- and Silane-Dependent Regioselectivities
作者:Chao Wang、Wei Jie Teo、Shaozhong Ge
DOI:10.1021/acscatal.6b02518
日期:2017.1.6
hydrosilylation of alkenes catalyzed by catalysts generated in situ from bench-stable Co(acac)2 and phosphine- or nitrogen-based ligands. A wide range of vinylarenes and aliphatic alkenes reacted to afford either branched (45 examples) or linear (37 examples) organosilanes in high isolated yields (average: 84%) and high regioselectivities (from 91:9 to >99:1). This transformation tolerates a variety of functional
set of base metal catalysts has been developed for regiodivergent alkene hydrosilylations: iron complexes of phosphine‐iminopyridine are selective for anti‐Markovnikov hydrosilylations (linear/branched up to >99:1), while the cobalt complexes bearing the same type of ligands provide an unprecedented high level of Markovnikov selectivity (branched/linear up to >99:1). Both systems exhibit high efficiency