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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: cupsoftea on December 11, 2014, 02:54:16 PM

Title: Chemoselectivity in reduction
Post by: cupsoftea on December 11, 2014, 02:54:16 PM

I did an experiment, reducing the following selectivity to target either functional group

{MOD Edit: snip out monster link to Google image search}

1) using Sn/HCl to reduce the NO2 group to NH2
2) using NaBH4 to reduce the carbonyl to an alcohol

In both cases the choice of reducing agent is selective

My understanding is that the NaBH4 is too mild to reduce the NO2 group

But I am not sure why the Sn/HCL doesn't reduce carbonyls?

Any suggestions much appreciated

Title: Re: Chemoselectivity in reduction
Post by: kriggy on December 19, 2014, 01:57:01 PM

I think that Sn/HCl can reduce carbonyl group, it depends on conditions

Title: Re: Chemoselectivity in reduction
Post by: Altered State on December 19, 2014, 06:13:21 PM

Following "Modern Projects and Experiments" (http://www.amazon.com/Modern-Projects-Experiments-Organic-Chemistry/dp/0716739216), you can indeed selectively reduce the nitro group of that compound using 1) Sn/HCl 2) NaOH/H2O

(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Fwww.foothill.edu%2Fpsme%2Farmstrong%2Fimages%2Freduction_sel.png&hash=a54f2a607bf6538668d30ecdb59040e9e9ee32e1)

Source:
http://www.foothill.edu/psme/armstrong/selectivereduction.shtml



Further reading: https://www2.chemistry.msu.edu/faculty/reusch/VirtTxtJml/chapt15.htm
(https://www2.chemistry.msu.edu/faculty/reusch/VirtTxtJml/Images2/subreduc.gif)

Note that even a benzaldehyde group is not reduced by Sn/HCl