# Why do Grignard reagents form? [closed]

Why does magnesium insert itself between a carbon atom and halogen atom? Can anyone give any vague idea about why this occurs?

Also does a Grignard reagent only form when there is carbon atom and halogen atom with single bond between them? For example, can magnesium insert between the carbon and oxygen atoms of a carbonyl?

## closed as unclear what you're asking by Jan, Todd Minehardt, Klaus-Dieter Warzecha, bon, paracetamolFeb 5 '17 at 4:59

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• Reactions happen because of decrease in chemical potential associated with it. More precisely they happen if activation energy is provided, products are stable thermodynamically or kinetically and there's a viable pathway for it. Are youu asking about pathway or what? – Mithoron Feb 2 '17 at 21:32

## 1 Answer

Yes, this is a very interesting question that till today, not everyone agrees the precise mechanism as to how it works. Here is one with homolytic fission:

For your second query, I don't think it is feasible as the $\ce{C=O}$ carbonyl bond is rather stable.

• The answer presents a mechanistic hypothesis, but the question is asking why the reaction happens. The answer needs to include some rationale why the mechanism makes sense. – jerepierre Feb 2 '17 at 19:24