I would like to react isocynate (NCO) to COOH or OH groups in DMSO environment. Do I need to activate the COOH or OH groups with carbonyldiimidazole? or do I need to use catalyst suchas triethylamine? Do I also need high temperature for reaction or is room temperature ok?
Usually isocyanates are quite reactive and don't need activation for reaction with good nucleophiles. If in your case the reaction does not happen, try to make sodium salt from your OH or COOH compounds (using NaH of t-BuONa, for example). Carbonyldiimidazole will not help you in this case.
Unless you have very special reason to use DMSO, I would recommend anhydrous THF, dioxane or any other low-boiling point aprotic solvent; this will make the isolation of your reaction product easier. I would start at room temperature and only heat it if the reaction would not proceed.
These are very general recommendations; if your reagents are kind of special, then you will need to make some adjustments.
Good luck.
Dear all, the following documents cover most facets of the question. My Regards
https://doi.org/10.1016/S0040-4039(00)84230-6
https://doi.org/10.1021/jo01089a024
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532007000600017
https://doi.org/10.1016/j.tetlet.2004.02.012
https://doi.org/10.1002/recl.19921110205
https://doi.org/10.1021/ol200531k
Isocyanates react with polyols either ....ether or ester based polyols. Amines can be incorporated as chain extenders and also catalyse the reaction. Reactions can be cold cure(Room temperature) or hot cure( 75-80 Degrees Celcius).
So it can be just a two component polyol and Isocyanate or three component Polyol + Isocyanate + amine giving rise to polyurethane.
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