I am looking for a way to change the amine functional group on a lysine to either an epoxide, thiol or a benzamide functional group. I am specific reactions to amine group on lysine and does not interact with guanidine functional group on arginine. I have been looking through the literature and cannot find anything. If you can find anything sources would be nice but any help would be much appreciated.

My guess (only a guess):

 

You can react it with HNO2 + H2SO4 to do a diazotization reaction.

you get something like R-----N₂⁺HSO₄^-

which can be substituted by almost any other functional group (like Br) over one or two step. then you can attach your desired stuff to R.

 

I have tried it on many hydrocarbons and it just worked fine. BUT I HAVEN'T TRIED IT ON Lycine OR OTHER AMINO ACIDS.

 

Source to read more if you want : McMurry Organic Chemistry 8th edition.

Edited June 22, 201312 yr by Bromo_DragonFly

Could you do a hoffman elimination to form an alkene followed by treatment with MCPBA to make an epoxide? I'm thinking maybe there would be some way to selectively alkylate the less sterically hindered amine.

A good place to start is protein modification books by Means and Feeney or by Roger Lundblad. N-hydroxysuccinimide esters are sometimes used to modify lysine residues in proteins. LInk.