synthesis of amine
Chemistry discussion, revision, exam and homework help.
-
- Reputation:
- Thread Starter
- Overlord in Training
synthesis of amineHey fellow organic chemists, some help here please. Do you think that would work? I would need to lithiate the protio ligand in the end for salt metathesis reaction but i figure an aqueous work up stage might be useful to just confirm that I have made it or something.
Thanks. Any advice is appreciated. -
- Reputation:
- Overlord in Training
- Posts: 2,522
Re: synthesis of amineObviously I don't know anything like as much as you do, but I haven't come across many examples of imines acting as electrophiles without first being protonated, which clearly wouldn't work in this case, but I can't see why it wouldn't work.(Original post by shengoc)
Hey fellow organic chemists, some help here please. Do you think that would work? I would need to lithiate the protio ligand in the end for salt metathesis reaction but i figure an aqueous work up stage might be useful to just confirm that I have made it or something.
Thanks. Any advice is appreciated.
We had a question in one of our exams this year involving synthesis of a tertiary amine. I'm fairly sure we hadn't covered any examples of this but guessed you might be able to react an imine with AlMe3 as I've seen similar sort of reactions, as you'd activate the imine by formation of the adduct first, before the methyl group is delivered to the carbon. Don't know if this would actually work though. -
- Reputation:
- Thread Starter
- Overlord in Training
Re: synthesis of amineI dealt with Schlenck line air-sensitive technique usually, so organic prep has never felt that easy. What I have made before have the isopropyls at the end - confirmed by x-ray of the lithiated compound. but these involve in-situ hydrogenation following the imine formation.(Original post by illusionz)
Obviously I don't know anything like as much as you do, but I haven't come across many examples of imines acting as electrophiles without first being protonated, which clearly wouldn't work in this case, but I can't see why it wouldn't work.
We had a question in one of our exams this year involving synthesis of a tertiary amine. I'm fairly sure we hadn't covered any examples of this but guessed you might be able to react an imine with AlMe3 as I've seen similar sort of reactions, as you'd activate the imine by formation of the adduct first, before the methyl group is delivered to the carbon. Don't know if this would actually work though.
Do you see any better synthetic strategies? -
- Reputation:
- Thread Starter
- Overlord in Training
Re: synthesis of aminehaha, yeah it is indeed an anagram of amine. you might like this then,
http://web.pdx.edu/~yanm/Chanteau.pdf
p/s - i love the nanoputians! -
- Reputation:
- Overlord in Training
- Posts: 2,522
Re: synthesis of amineThe only other thing I can think of is whether you could use a simple Sn1 synthesis with t-BuCl or something similar, as because the t-Bu group is so large, you probably wouldn't get repeated substitution? (cf t-BuO is a non nucleophilic base)?(Original post by shengoc)
I dealt with Schlenck line air-sensitive technique usually, so organic prep has never felt that easy. What I have made before have the isopropyls at the end - confirmed by x-ray of the lithiated compound. but these involve in-situ hydrogenation following the imine formation.
Do you see any better synthetic strategies? -
- Reputation:
- Junior Member
- Location: Sheffield
- Posts: 27
Re: synthesis of amineI really doubt that your proposed methylation of the 'spermidine'-esk ligand would work, the imine just wouldn't be electrophillic at all as its electron rich. If the amine had an EWG on it, then it would be more plausible, but that would need alot of time and effort to play around with.
I think you would be better off trying a simple alkylation as said above, the sterics are in your favour. Di-t-butylamine is impossible to make by itself, so i think you've got good odds of mono-alkylation.
If not, it maybe be favorable to start with t-butyl amine and then build from there. -
- Reputation:
- Thread Starter
- Overlord in Training
Re: synthesis of aminethe thing is guys, in presence of AlCl3, if MeLi is used, LiCl would definitely be precipitated out. some MeLi would also be strong enough base to deprotonate the more acidic methyl protons.
the same problems are envisaged with the use of grignards. we are not very keen on a 3 carbon backbone but mainly on the 2 carbon backbone for structural and reactivity comparisons.
sigh, this amine seems hopeless to be synthesised. -
- Reputation:
- Overlord in Training
- Posts: 2,522
Re: synthesis of amineSurely the sterics will be in your favour for the following to work?(Original post by shengoc)
the thing is guys, in presence of AlCl3, if MeLi is used, LiCl would definitely be precipitated out. some MeLi would also be strong enough base to deprotonate the more acidic methyl protons.
the same problems are envisaged with the use of grignards. we are not very keen on a 3 carbon backbone but mainly on the 2 carbon backbone for structural and reactivity comparisons.
sigh, this amine seems hopeless to be synthesised.
-
- Reputation:
- Thread Starter
- Overlord in Training
Re: synthesis of amineyou are suggesting double lithiation of the protio ligands and then tBuCl - where LiCl precipitates out and hopefully we get the desired product?
but like the other poster said, nucleophilic substitution with amines tend to lead to quaternary amine. Surely, that amine you have is more reactive electronically though less so sterically but still the lone pair could be quite accessible. -
- Reputation:
- Overlord in Training
- Posts: 2,522
Re: synthesis of amineI wouldn't have thought you'd even need to lithiate the amine.(Original post by shengoc)
you are suggesting double lithiation of the protio ligands and then tBuCl - where LiCl precipitates out and hopefully we get the desired product?
but like the other poster said, nucleophilic substitution with amines tend to lead to quaternary amine. Surely, that amine you have is more reactive electronically though less so sterically but still the lone pair could be quite accessible.
Also, I very much doubt that you'd get the tertiary amine in this case. The steric demand of having two t-Bu groups and a straight chain alkyl around 1 nitrogen is too great. The steric effects should dominate the electronic ones. -
- Reputation:
- Thread Starter
- Overlord in Training
Re: synthesis of amineI will let the post-doc who supervised me know about this - maybe he can get something out of this synthetic pathway.(Original post by illusionz)
I wouldn't have thought you'd even need to lithiate the amine.
Also, I very much doubt that you'd get the tertiary amine in this case. The steric demand of having two t-Bu groups and a straight chain alkyl around 1 nitrogen is too great. The steric effects should dominate the electronic ones.
By the way, I am moving to Cambridge this October! -
- Reputation:
- Overlord in Training
- Posts: 2,522
Re: synthesis of amineAh cool, which group are you going to be with?(Original post by shengoc)
I will let the post-doc who supervised me know about this - maybe he can get something out of this synthetic pathway.
By the way, I am moving to Cambridge this October! -
- Reputation:
- Thread Starter
- Overlord in Training
Re: synthesis of amineDom Wright's(Original post by illusionz)
Ah cool, which group are you going to be with? -
- Reputation:
- Overlord in Training
- Posts: 2,522
Re: synthesis of amineYou've done well there, Dom's a really nice guy. I tried to do a project with him but he's not taking any 4th years next year.(Original post by shengoc)
Dom Wright's -
- Reputation:
- Thread Starter
- Overlord in Training
Re: synthesis of amineshame; my supervisor here, Philip is also not taking any 4th year Part IIs for next year. who you going to work for next year then? your chemistry department is very impressive btw.(Original post by illusionz)
You've done well there, Dom's a really nice guy. I tried to do a project with him but he's not taking any 4th years next year.
-
- Reputation:
- Overlord in Training
- Posts: 2,522
Re: synthesis of amineI haven't found out yet(Original post by shengoc)
shame; my supervisor here, Philip is also not taking any 4th year Part IIs for next year. who you going to work for next year then? your chemistry department is very impressive btw.
