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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: CHEKAL on December 12, 2012, 12:38:44 PM

Title: Chrial Nucleophile
Post by: CHEKAL on December 12, 2012, 12:38:44 PM: Can anyone suggest a chiral nucleophile so this prochiral eta-3 complex becomes chiral? how would it attach?

Thanks :)
Title: Re: Chrial Nucleophile
Post by: discodermolide on December 12, 2012, 12:40:08 PM: Which complex, can you draw it and post the structure?
Title: Re: Chrial Nucleophile
Post by: CHEKAL on December 12, 2012, 12:44:14 PM: Quote from: discodermolide on December 12, 2012, 12:40:08 PM
Which complex, can you draw it and post the structure?

sorry forgot to click upload!
Title: Re: Chrial Nucleophile
Post by: discodermolide on December 12, 2012, 12:52:12 PM: How about an amino acid? Cysteine.
Title: Re: Chrial Nucleophile
Post by: CHEKAL on December 12, 2012, 12:59:41 PM: could i use a grignard reagent? how would it add to the complex?
Title: Re: Chrial Nucleophile
Post by: discodermolide on December 12, 2012, 01:16:42 PM: I was thinking of displacing one of the carbonyls
Title: Re: Chrial Nucleophile
Post by: CHEKAL on December 12, 2012, 01:31:02 PM: its got to be chiral, i need to modify the eta structure, should be a simple chiral nucleophile to add, any other ideas?
Title: Re: Chrial Nucleophile
Post by: discodermolide on December 12, 2012, 01:42:38 PM: How about a chiral boron reagent?
Title: Re: Chrial Nucleophile
Post by: CHEKAL on December 12, 2012, 03:02:53 PM: that could work, would it add to one side of the multiple bonds leaving the other side a double bond to the other ph group? would the metal un-complex?
Title: Re: Chrial Nucleophile
Post by: discodermolide on December 12, 2012, 09:42:00 PM: It may do that I'm not sure. You have an allylic double bond so I assume it would add normally.
I have no idea if it would un-complex the metal. If the C=C is gone then it may do.
Title: Re: Chrial Nucleophile
Post by: Gibbs on December 14, 2012, 05:00:52 PM: It could indeed un-complex to leave a double bond. A simple chiral nucleophile would be a modified Lithium diisopropylamide (LDA) Just modify it so you form a chiral carbon on one of the alkyl parts. The good thing about using Nitrogen as the bonding point is that you need not worry about having two chiral centers next to one another as nitrogen cannot form a chiral centre. Reacting a chiral nucleophile with a PROCHIRAL electrophilic multihapto complex would yield a pair of epimers.