In heterogeneous catalysis, the catalyst is in a different phase from the reactants. category: catalyst-palladium, At least one of the reactants interacts with the solid surface in a physical process called adsorption in such a way. 72287-26-4, name is [1,1′-Bis(diphenylphosphino)ferrocene]dichloropalladium(II). In an article£¬Which mentioned a new discovery about 72287-26-4
Stereochemistry of eudesmane cation formation during catalysis by aristolochene synthase from Penicillium roqueforti
The aristolochene synthase catalysed cyclisation of farnesyl diphosphate (1) has been postulated to proceed through (S)-germacrene A (3). However, the active site acid that reprotonates this neutral intermediate has so far proved difficult to identify and, based on high level ab initio molecular orbital and density functional theory calculations, a proton transfer mechanism has recently been proposed, in which proton transfer from C12 of germacryl cation to the C6,C7-double bond of germacryl cation (2) proceeds either directly or via a tightly bound water molecule. In this work, the stereochemistry of the elimination and protonation reactions was investigated by the analysis of the reaction products from incubation of 1 and of [12,12,12,13,13,13- 2H6]-farnesyl diphosphate (15) with aristolochene synthase from Penicillium roqueforti (PR-AS) in H2O and D2O. The results reveal proton loss from C12 during the reaction and incorporation of another proton from the solvent. Incubation of 1 with PR-AS in D2O led to the production of (6R)-[6-2H] aristolochene, indicating that protonation occurs from the face of the 10-membered germacrene ring opposite the isopropylidene group. Hence these results firmly exclude proton transfer from C12 to C6 of germacryl cation. We propose here Lys 206 as the general acid/base during PR-AS catalysis. This residue is part of a conserved network of hydrogen bonds, along which protons could be delivered from the solvent to the active site.
I hope this article can help some friends in scientific research. I am very proud of our efforts over the past few months and hope to 72287-26-4, help many people in the next few years.category: catalyst-palladium
Reference£º
Chapter 1 An introduction to palladium catalysis,
Palladium/carbon catalyst regeneration and mechanical application method