[HP]

Hi friends,
My new topic is a question about possible reactions between aliphatic aldehydes with amides for example:
R-CH2CHO + R1NHCOR2, heat -->  
I think first about reaction carbonyl with NH, which though weak acid in heating may be this happen, and what about some acid catalyst:
R-CH2CHO + R1NHCOR2 --> R-CH2CH(OH)N(R1)-COR2 (1)
Then after dehydration step this aduct should lead to:
R-CH=CH-N(R1)-COR2 (2)
This product is something like a Schiff base but of amide and now i can't name it right
Also thinking and about possible intramolecular condensation between aducts forming ether bonds (1):
 2R-CH2CH(OH)N(R1)-COR2 -->R-CH2CH--O--CH---R
Please if any one is competent such type condensation reactions of aldehydes/amides or know something to share his knowledge with me in this discussion.
Regards from here raining

[Albert]

I looked for 'amide aldehyde condensation' on Google and I found this article. It sounds interesting, although you might have already read it: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14502613&dopt=Abstract

Greetings from rainy and windy Amsterdam.

[HP]

Thank you for the reply,, I also googled my search and found some articles on this subject but there weren't any detailed mechanism this reactions given. And also i couldn't find any example of this type reactions of amides with aldehydes. So if anyone have book source this subject pls for share
In theoretical plan i continue discussion on possible etherification reaction between aducts (1) as i described prev...So where H2O will come from, or is possible the both dehydration step reactions 
Thank you

[leeying]

If you want  acid catalysts, there are some oxides acted as acid catalysts. eg: CuO,Co3O4,Fe2O3

[HP]

Hm that sounds interesting... And do you have any hint how these Me-oxides act as catalysts for this type condensation ? I mean if they form some intermediate compound with one of the reagents eg aldehyde or amide. I can imagine only some reaction of the amide NH with these amphoteric oxides forming oxohydroxyde and N:-Me+ also know that amides form some complex compounds with trans metal compounds like GaCl3 which break out the inter and intra H-bonds and also coordinate with N-e-pair...About aldehydes and Me-oxides i know few : as i remember when EtOH pass true heat Cu wire it oxidise to acetaldehyde which may further oxidise to acetic acid, and as i remember CuO have some role these transformations also Co-catalyst in the Wacker process
Well i am still looking for my detail mechanism these condensations and i am close i think and hope Though it seems to be a well working reaction it's strange it's not mentioned in the books i have which is pitty (for books:).

[wereworm73]

In this document, the first step of the amidocarbonylation reaction mechanism (under Scheme 2)  involves a reversible condensation of an aldehyde and acetamide. 

http://stratingh.eldoc.ub.rug.nl/FILES/root/VriesJGde/1996/JOrgChemdeVriesJG/1996JOrgChemdeVriesJG.pdf

[HP]

Thank you for the nice article - it get inlight me to some extend It's interesting that described amidocarbonylation is revirsible and on the 2nd stage: R-CH=CH-NHCO-CH3. I think this compound is similar to some extend to Schiff bases which readily hydrolyze but do you think NHCO bond may act as stbilizing group and what tautomerism possible 

[wereworm73]

I think the enamide could tautomerize to form R-CH2-C=N-CO-CH3, but they probably left it out of the mechanism because the enamide is the species reacting with the cobalt compound.  Unless the conditions are strongly acidic or basic, I don't think the enamide would hydrolyze because the N-CO- group is pretty stable.

[HP]

Yah you are right about this possible tautomerization - its something as nonexisting ethyleneamine to ethylimine:
 CH2=CH-NH2<--->CH3-CH=NH  But what if R1-CH=CH-N(CH3)-CO-R2, then i think such tautomerism is imposible and enamide the only possible product...About hydrolyze stability it's really interesting and i dont have specific knowledge - we all know about hydrolysis of amides in basic or acidic conditions but what about in this compounds where have conjugated 2 bond system between N-atom more or less stable Also if these compounds hydrolyze in basic media do you think it's possible the released free aldehyde in situ do further aldol condensations...