From owner-chemistry@ccl.net Sun Oct  2 13:45:00 2011
From: "Arne Dieckmann adieckma%x%googlemail.com" <owner-chemistry###server.ccl.net>
To: CCL
Subject: CCL: Question on catalytic mechanism
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X-Original-From: Arne Dieckmann <adieckma!=!googlemail.com>
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Date: Sun, 2 Oct 2011 10:05:15 -0700
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Sent to CCL by: Arne Dieckmann [adieckma a googlemail.com]
Hi Sergio, 

could you point us to a paper postulating these carbanions? This sounds highly unlikely to me. Also, you do not need to deprotonate an amino-group to facilitate the attack to an epoxide. Normally, the amino-group would attack and lose a proton to the alcohol oxigen afterwards. 


Cheers, 
Arne

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
Dr. Arne Dieckmann
Houk Research Lab
University of California, Los Angeles 
email: adieckma-,-googlemail.com


On Oct 2, 2011, at 8:57 AM, Sergio Manzetti sergio.manzetti]![gmail.com wrote:

> 
> Hi everyone,  the adduct formation between epoxides and guanosine amine groups has been postulated by several sources to occur through the formation of a carbanion. However, I cannot fit in the description of the reactants how it is possible for the epoxy-carbon in a epoxy-PAH to gain a negatiive charge when the epoxy oxygen really deprotonates the amine group first.
> 
> Does someone know if these sources quoting carbanions really ment carbocations?
> 
> Best wishes
> 
> Sergio
> 
>