dean stark
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Stereoselective N-alkylation of ketimines
Possibly an odd question, but...
It's pretty common to see enantiopure alpha-methylbenzylamine being used in amination reactions where the imine is hydrogenated e.g. by trichlorosilane*.
I'm just wondering if there is any evidence of N-alkylation as in Klute's example to yield the corresponding secondary amine after hydrolysis with any degree stereoselectivity? Does that even makes sense?
Thanks in advance...
* This is a cool paper. DMF is used as a ligand for the reduction of said imines via trichlorosilane, with high yield and very high ee. (Hint: if
someone with access to Synthesis feels like slinging me this paper, feel free =)
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Nicodem
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You might want to clarify what you are talking about. N-Alkylation of enantiopure alpha-methylbenzylamine derived imines can not give enantiomeric
excess of secondary amines, because secondary amines don't have a stereogenic N-atom (see nitrogen inversion), while other atoms are not affected or prochiral. Only C-alkylation of imines at the alpha position can give enantiomeric
excesses, but it does not appears that you are talking about that.
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dean stark
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That makes sense. I guess I figured that since adding hydrogen across the double bond (to both C and N) is stereoselective, that adding an alkyl (to
the N) might be as well.
Thanks for the explanation.
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