[Sis290025]

I am unsure of the following answers to these questions. Any help would be appreciated.

1. Which of the following functional groups react with Grignard reagents: alkenes; terminal alkynes; nonterminal alkynes; alcohols; alkanes; tertiary amines; secondary amines?

I know Grignard reagents react with electrophiles. This would include alcohols, secondary and tertiary amines?

2. True or false: You can form a Grignard in the presence of an alcohol. Explain your answer.

This is false because alcohol has an -OH group. The Grignard reagent would decompose since the products that would follow would be a hydrocarbon R-CH and a Mg salt, HO-Mg-Br.

Thanks.

[Ψ×Ψ]

#2: What functional group is present in the product when a ketone reacts with a Grignard reagent?  Think about this one for a minute...

Although, since I have never successfully run one of these accursed reactions, I might not be the best person to ask.

[Mitch]

#2 Is true, if you use more grignard reagent than -OH functional groups.

[AWK]

http://en.wikipedia.org/wiki/Grignard_reagent

[Dan]

1. Which of the following functional groups react with Grignard reagents: alkenes; terminal alkynes; nonterminal alkynes; alcohols; alkanes; tertiary amines; secondary amines?

I know Grignard reagents react with electrophiles. This would include alcohols, secondary and tertiary amines?

Alcohols and amines are not electrophiles, they are nucleophiles.

Grignards are nucleophilic too, but they also have another reactive property...
hint: grignard reagents are destroyed by water for this reason.

[Sis290025]

#2: What functional group is present in the product when a ketone reacts with a Grignard reagent? Think about this one for a minute...

A carbonyl group is present in the ketone, but none of the answer choices has a carbonyl group.

Would it be alcohols, terminal alkynes, and secondary amines?

[AWK]

The question was - which react? - that means - give Grignard reaction or decompose Grignard reagent.
Answer is: terminal alkynes; alcohols; secondary amines.

[Silica]

"Preparing" a Grignard reagent in an alcohol solvent has been done.

I'll try and find the reference, but it was hown that in CH3OD solvent, organic bromides react with magnesium metal to form deuterated organics.  This was presented as evidence that free radicals diffusing freely in solution are not intermediates in Grignard reactions, since a free radical would abstract a hydrogen atom from the CH3 group, giving rise to a non-deuterated organic, whereas a carbanion-type species would remove a proton (or deuteron) from the acidic hydroxyl group.

I guess there is a lot of room for arguments about whether it's acually a Grignard reaction that's occurring.  The observed fact is that the products look as if they came from carbanions and not radicals.

This a a nice way to introduce a single deuterium atom into a molecule, by the way.  Very clean reaction and easy to work up.