JandaJel as a polymeric support to improve the catalytic efficiency of immobilized-1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) under solvent-free conditions
JandaJel, with its greater spacing between the linear polymeric chains compared to that of polystyrene matrices, is a very efficient support for improving the catalytic efficiency of TBD under SolFC.
Chiral Lanthanoid Dimers Ligated by Carbohydrate‐Based Diketonates: Catalytic and Luminescent Properties
作者:William J. Gee、Judith Hierold、Jonathan G. MacLellan、Philip C. Andrews、David W. Lupton、Peter C. Junk
DOI:10.1002/ejic.201100505
日期:2011.9
hydrated lanthanoid chlorides (Ln = La, Eu) with chiral, carbohydrate-based diketonate ligands has yielded dimeric species with Ln2L6 composition as determined by MALDI mass spectrometry and single-crystal X-ray crystallography. The X-ray crystallographic analysis identified a chiral cavity formed by interligand repulsion able to coordinate dimethylformamide, prompting investigation of the catalytic properties
水合镧系元素氯化物(Ln = La,Eu)与手性、基于碳水化合物的二酮配体的反应产生了具有 Ln2L6 组成的二聚体,如 MALDI 质谱法和单晶 X 射线晶体学所确定。X 射线晶体学分析确定了一个由配体间排斥形成的手性腔,能够协调二甲基甲酰胺,促使研究二聚体的催化性能。初步结果表明,二聚体在硫代-迈克尔加成反应以及铕的金属基发光中显示出催化活性。
E-factor minimized protocols for the polystyryl-BEMP catalyzed conjugate additions of various nucleophiles to α,β-unsaturated carbonyl compounds
作者:Simona Bonollo、Daniela Lanari、Julie M. Longo、Luigi Vaccaro
DOI:10.1039/c1gc16088e
日期:——
Efficient protocols for the addition of carbon-, sulphur- and nitrogen-nucleophiles to α,β-unsaturated carbonylcompounds catalyzed by PS-BEMP have been reported. The adoption of solvent-free conditions (SolFC) was crucial for improving the efficiency of all the processes, while by using an organic reaction medium poor results were obtained. Addition reactions were performed by using equimolar amounts
This report concerns Lewis acid catalyzed enantioselective sulfa-Michael addition in neutral water by using a very efficient Sc(OTf)(3)/bipyridine 1 catalytic system. It is noteworthy that the protocol presented employs water as a reaction medium and allows us to obtain very high stereoselectivity and satisfactory yields for beta-keto sulphides deriving from aliphatic thiols. The recovery and reuse of both the aqueous medium and the catalytic system is also reported.