Chemical Forums

Chemistry Forums for Students => Organic Chemistry Forum => Organic Chemistry Forum for Graduate Students and Professionals => Topic started by: kamiyu2550 on September 27, 2019, 10:22:07 AM

Title: What is your most important organic reaction in your professional life
Post by: kamiyu2550 on September 27, 2019, 10:22:07 AM
In your professional life (e.g. PhD or professional workers), which organic reaction is most important to you?
Title: Re: What is your most important organic reaction in your professional life
Post by: rolnor on September 28, 2019, 03:47:57 AM
It depends on the project, not possible to generalize.
Title: Re: What is your most important organic reaction in your professional life
Post by: Babcock_Hall on September 30, 2019, 10:52:10 AM
Substitutions involving the trifluoromethanesulfonyl group leaving have helped me twice at different points in my career.
Title: Re: What is your most important organic reaction in your professional life
Post by: kamiyu2550 on September 30, 2019, 11:28:24 AM
Substitutions involving the trifluoromethanesulfonyl group leaving have helped me twice at different points in my career.

I guess what you did is using triflate as pseduo-halide in cross-coupling reaction, right?

For simple SN2 reaction people may use OTs group as it is way cheaper.

Triflate reactivity in between iodine and bromine.
Title: Re: What is your most important organic reaction in your professional life
Post by: Babcock_Hall on September 30, 2019, 04:08:25 PM
I used trimethylsilyl trifluoromethanesulfonate and tetrabutylammonium iodide in place of TMSI.  I was trying to remove the methyl ester groups from a very labile phosphate ester.  TMSI is not the easiest compound with which to work.
Title: Re: What is your most important organic reaction in your professional life
Post by: kamiyu2550 on September 30, 2019, 06:54:46 PM
I used trimethylsilyl trifluoromethanesulfonate and tetrabutylammonium iodide in place of TMSI.  I was trying to remove the methyl ester groups from a very labile phosphate ester.  TMSI is not the easiest compound with which to work.

Ok, I see. Please confirm my logic here:

TMSI is very reactive and hard to handle and you wanna make it in situ. TMSI in this case serves as a very mild deprotecting agent. For your methyl phosphate ester, the reaction with TMSI will give TMS phosphate and methyl iodide.

Is this correct?
Title: Re: What is your most important organic reaction in your professional life
Post by: Babcock_Hall on September 30, 2019, 07:45:35 PM
Yes; if memory serves me, we ran the reaction at -30 °C in DCM.  Once you have a trimethylsilyl phosphate ester, that sort of compound is very easily solvolyzed in alcohols or in water, sometimes in the presence of a weak base.
Title: Re: What is your most important organic reaction in your professional life
Post by: Reddart on April 19, 2020, 09:14:24 PM
The thiol-ene reaction. I have used it successfully for the last 3 companies I've worked at, and if the desired properties are met of my latest batch of compounds, my current company as well.
Title: Re: What is your most important organic reaction in your professional life
Post by: kamiyu2550 on April 20, 2020, 12:27:05 PM
The thiol-ene reaction. I have used it successfully for the last 3 companies I've worked at, and if the desired properties are met of my latest batch of compounds, my current company as well.

Yup, this is really a versatile reaction, which can be used for crosslinking/polymerization. My colleagues for postdocs use this reaction a lot.

By the way, I think thiol-ene reaction is effected by AIBN or photoinitiator, right? Any other possible choice?
Title: Re: What is your most important organic reaction in your professional life
Post by: OrganicDan96 on April 20, 2020, 05:24:55 PM
synthesis of amides using pentafluorophenyl esters are a reaction i do all the time
Title: Re: What is your most important organic reaction in your professional life
Post by: kamiyu2550 on April 20, 2020, 05:57:26 PM
synthesis of amides using pentafluorophenyl esters are a reaction i do all the time

This chemistry relies mainly on the easy leaving of pentafluorophenoxide group, is this true? Did I miss anything here?
Title: Re: What is your most important organic reaction in your professional life
Post by: hypervalent_iodine on April 20, 2020, 08:33:44 PM
Reactions I’ve done a lot of: making difficult amides in every way imaginable.

More broadly, I’d say the thing that has saved me the most in reactions I’ve had a hard time with are phase transfer catalysts, and having access to the Starks PTC text.
Title: Re: What is your most important organic reaction in your professional life
Post by: OrganicDan96 on April 21, 2020, 06:07:49 AM
synthesis of amides using pentafluorophenyl esters are a reaction i do all the time

This chemistry relies mainly on the easy leaving of pentafluorophenoxide group, is this true? Did I miss anything here?

yeah that's right, it's a great way of making amides as purification is normally really easy (no concerns about excess coupling reagent) and pentafluorophenyl esters are extremely stable and can be stored at room temperature in air for months or years with no degradation like you might expect for succinamides or acid chlorides
Title: Re: What is your most important organic reaction in your professional life
Post by: Guitarmaniac86 on April 21, 2020, 01:13:29 PM
Right now, Suzuki, Ullmann, and Buchwald couplings. I do these every day.

I'll say one thing. I do not like Ullmann couplings. Dirty, harsh, annoying to work with. Some reactions go fine, others need a constant feeding with catalyst and ligand.
Title: Re: What is your most important organic reaction in your professional life
Post by: kamiyu2550 on April 21, 2020, 01:30:07 PM
Right now, Suzuki, Ullmann, and Buchwald couplings. I do these every day.

I'll say one thing. I do not like Ullmann couplings. Dirty, harsh, annoying to work with. Some reactions go fine, others need a constant feeding with catalyst and ligand.

Agreed. I have done Ullmann a lot (for C-I and N-H coupling) in my Master degree. It is always a black mass. But good stuff is obtained after column chromatography
Title: Re: What is your most important organic reaction in your professional life
Post by: Reddart on April 22, 2020, 01:13:54 PM
The thiol-ene reaction. I have used it successfully for the last 3 companies I've worked at, and if the desired properties are met of my latest batch of compounds, my current company as well.

Yup, this is really a versatile reaction, which can be used for crosslinking/polymerization. My colleagues for postdocs use this reaction a lot.

By the way, I think thiol-ene reaction is effected by AIBN or photoinitiator, right? Any other possible choice?
Yes, some kind of radical generator. I have mostly used AIBN thermal initiation, but some use photo-initiators successfully. Supposedly, you can just use UV light alone at the appropriate wavelength and intensity to initiate, but I have never tried that.
Title: Re: What is your most important organic reaction in your professional life
Post by: wildfyr on April 22, 2020, 07:06:30 PM
Yes, plain UV works excellently. Its not exactly a stable mixture as it is. If you leave them in the dark then autopolymerization will occur between primary thiols and alkenes.