[frostbite]

I am in need help here. I am pretty sure that Cbz protective groups can be removed from primary amino acids by hydrogenolysis in a solution of K2CO3 in MeOH and H2O, but cannot figure out the mechanism. Any assistance here would be greatly appreciated. Typical protocol is Pd/C but I do not want that method.

Tracy

[Honclbrif]

Not sure about those particular conditions, I'll refer you to Greene for it. As for the mechanism: Its simple benzyl deprotection of the O-benzyl carbamate yielding a carbamic acid which decays to CO2 and the amine. The last step (formation of a carbamic acid which decays) is common to virtually all carbamate deprotections.

[frostbite]

Thanks. I have Greene's book but has different catalytic conditions for the removal of CBz. I am drawing a blank for some reason. I am not sure what role the H2O plays in the reaction scheme. The K2CO3 gives the basic conditions, correct?

Tracy

[Honclbrif]

Are you considering just dissolving the Cbz-protected amine in the methanolic carbonate without hydrogen or a hydrogenation catalyst? I doubt that would work. Its my understanding that on its own, Cbz is pretty stable toward basic conditions. However, the methanolic carbonate should be pretty mild, so its worth trying out. Unless your substrate is ridiculously sensitive, the worst thing which would probably happen is you'd recover the starting material.

[Doc Oc]

Why don't you want to do the standard hydrogenolysis using Pd?  I've done that before and it works beautifully, you can run the reaction at ambient pressure/temp and then just filter off your product.