Baphomet - 4-11-2008 at 22:46
This ref speaks of reductive amination of glucose with ammonium sulfate:
linkinghub.elsevier.com/retrieve/pii/0003269779903415
"Glucose (0.08 mol) was reductively aminated at 105C for 4 h with 0.05 ml of various concentration of NaBH3CN in saturated ammonium sulfate."
(I don't have the full article yet)
Has anyone had experience with such a scheme? Or any opinion regarding it?
- Does it need the high temperature?
- Can the cyanoborohydride be replaced by an Al/Hg?
- Slight molar excess of the salt?
- What happens to the sulfate ion? Surely it does not produce H2SO4?
Thanks 
Baphomet - 4-11-2008 at 22:50
Is it even strong enough to reduce SO4[2-] to sulfur and water??
Klute - 4-11-2008 at 23:43
I don't think you can use anything but NaBH3CN, there is some similar work using ammonium acetate instead of the sulfate, and the yields where
mediocre anyway IIRC. Ammonium sulfate might even be less effective for solubility reasons.
Nicodem - 4-11-2008 at 23:48
Reductive amination with sodium cyanoborohydride is one of the most classic methods and only one of the few that actually work with ammonia derived
imines as well and in the presence of water. You can find thousands of examples in the literature. The ammonium sulfate is used as a source of ammonia
because it is also an acid at the same time, and the reductive aminations with NaBH3CN only work in acidic H2O/MeOH or aqueous media (at pH 3-5, if I
remember correctly). You can also use ammonium chloride if you prefer. Search the literature for more information. Surelly there must also be some
review paper on NaBH3CN use.
Baphomet - 5-11-2008 at 00:53
Thanks for the information guys. NaBH3CN / NaBH4 are difficult for me to get, maybe time to buy an electric car?