The computations not only confirmed the previously proposed mechanism that coordination of BF3 (as Lewis acid catalyst) to the acetal oxygen atom triggers 1,5-hydride transfer from the u03b1-C(sp3)-H bond to the alkenic carbon, followed by 1,6-cyclization (Cu2013C bond formation) between ...
At the same time, the Lewis acid catalyst can also improve the selectivity and yield of the ester exchange reaction. 13.由于酯交换反应机理的研究,我们可以更好地理解这一反应的发生过程。 Through the study of the mechanism of ester exchange reaction, we can better understand the process of this ...
Mechanism of glucose isomerization using a solid Lewis acid catalyst in water[J]. Angewandte Chemie, 2010, 122(47):9138-9141. https://doi.org/10.1002/ange.v122.47 https://onlinelibrary.wiley.com/toc/15213757/122/47 本文引用 [1] [9] Bermejo-Deval R, Orazov M, Gounder R, et al...
Davis, Mechanism of Glucose Isomerization Using a Solid Lewis Acid Catalyst in Water, Angew. Chem. Int. Ed. 49 (2010) 8954-8957.YuriyRomán‐Leshkov,ManuelMoliner,Jay A.Labinger,Mark E.Davis.Mechanism of Glucose Isomerization Using a Solid Lewis Acid Catalyst in Water[J]. Angewandte Chemie...
Lewis Acid Catalyzed Carbonyl-Ene Reaction Michael Ober 12/16/03 H C O + H O C R R R R LA The Hetero-Ene Reaction H X Y + H Y X X=Y : C=C, C=O, C=N, C=S, O=O, N=N (1) All-carbon ene-reactions: takes place between an olefin ...
Scheme 5. Proposed mechanism. Conclusion In conclusion, a Lewis acid-catalyzed Pudovik reaction–phospha-Brook rearrangement sequence between diarylphosphonates or -phosphinates and α-pyridinealdehydes was developed. This approach provides an efficient approach towards phosphoric esters and provides a scope...
Fringuelli F,Pizzo F,Vaccaro, L.AlCl3 as an efficient Lewis acid catalyst in water. Tetrahedron Letters . 2001F Francesco,P Ferdinando,V Luigi. AlCl3 as an efficient Lewis acid catalyst in Water[J].Tetrahedron Letters,2001,(06):1131-1133.doi:10.1016/S0040-4039(00)02164-X....
New enzyme catalysts are usually engineered by repurposing the active sites of natural proteins. Here we show that design and directed evolution can be used to transform a non-natural, functionally naive zinc-binding protein into a highly active catalyst
To gain insight into the mechanism of tandem isomerization/α-Michael addition, some control experiments were carried out. Firstly, we wondered why the addition of NEt3led to an increase in diastereoselectivity (Table1, entry 6). Treating the product2a(2.9:1 dr, 85%/12% ee) under the stand...
the polymer layer, which grows with the increasing pH for all precursors used. This indicates that the presence of metal ions—as a Lewis acid—has catalytic properties on the ongoing Michael addition reaction and the formation of the PDA layer, regardless of its solubility or dissociation [21]...