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Frequently Asked Question
Questions asked by users might not always be phrased in the clearest way.
The reaction with pd acetate, SPhos in PhMe/H2O and K3PO4 become dark when heating. Does it mean the catalyst is inactive?
Accepted Answer
The darkening of the reaction mixture could indicate several things. It's not necessarily a sign of catalyst deactivation. Possible reasons include:
Formation of colored byproducts: The reaction might be generating colored compounds, which is common in organic synthesis.
Decomposition of the catalyst: The Pd acetate or SPhos ligand could be decomposing at elevated temperatures, leading to color changes.
Reaction progress: The color change could be related to the consumption of reactants or the formation of products, even if the catalyst remains active.
To determine the cause, you'd need to further analyze the reaction mixture. Techniques like TLC, GC-MS, or NMR spectroscopy could help identify the colored species and determine if the catalyst is still active.
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