In my textbook of organic chemistry by francis carey 11th edition, the Corey-house synthesis is elaborated on in the topic of organocopper reagents. It is mentioned that as the R-X alkyl halide is added to the [R-Cu-R]- group, the electron count of copper increases from 14 to 16 and the oxidation state increases from +1 to +3. I interpreted this as a "driving force" to make sense of why this reaction occurs and why it was mentioned. the driving force being that as long as the reaction makes the electron count of copper approach 18, it is favoured.enter image description here

however this driving force does not hold for the reductive elimination part of the Corey-House synthesis where the electron count of copper is reduced from 16 to 14. it was mentioned that this decreases the oxidation state from +3 to +1.enter image description here

It seems very strange to me that in the oxidative addition, the reaction is favoured due to increase of electron count but the reductive elimination is favoured due to a more preferrable oxidation state of copper. it does not feel fair as it can be seen the other way around, where oxidative addition is not favoured due to change in oxidation state and reductive elimination is not favoured due to change in electron count.

So my questions would be what exactly drives the reaction forward? It does not feel right to use separate driving forces for this scenario. And instead of oxidative addition and reductive elimination, is it possible that the ligands reversibly bind to the copper? and the R-R' desired product is formed when the reverse reaction occurs,where they are unbound from the copper and bind to each other

  • 1
    $\begingroup$ This mechanistic fluff is irrelevant as far as "why reaction happens" is concerned - delta G of reaction is. $\endgroup$
    – Mithoron
    Jul 9, 2021 at 23:34
  • $\begingroup$ @Mithoron why is that so? $\endgroup$ Jul 10, 2021 at 0:28
  • $\begingroup$ Because that's how thermodynamics works? Thermodynamic functions of substrates and products (and irreversible steps if there are any) - that's important. $\endgroup$
    – Mithoron
    Jul 10, 2021 at 0:37
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    $\begingroup$ In general metal halide salts have high lattice enthalpies, which make them very stable compared to metal alkyl or alkyl halide reactants. This isn't always true, but most of the times, the driving force is the high lattice enthalpy of the salt i.e. thermodynamics. $\endgroup$
    – S R Maiti
    Jul 10, 2021 at 3:20
  • $\begingroup$ @Mithoron sorry i should rephrase. Is it not possible for both the mechanism and ▵G to work together to come up with a good explanation? $\endgroup$ Jul 10, 2021 at 14:39


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