One problem limiting the rxn scope and catalyst preformance is the the high-oxidative potencial of the hypervalenc iodine compund such as pida, pifa.
here I propose a new oxidant which is a imidoiodo compound with a bulky blocking group attached to the imine. It is a milder oxidant than the pida/pifa and with a certain sized bulky group, the oxidant might be able to exchange its iodo with a carbamte but not able to react with the metal like rhodium.
Such a setup can increase the catalyst scope and performance and also milder the rxn condition.
This is a good idea, but the problem is how can we generate the reactive especies. In older times I was working in this topic, and the results were frustrating. Perharps any new result in the last years? My chemistry is quite different now and I am not updated
ReplyDeletereactive species?
ReplyDeletenow it is clear that the active species in the C-h amination is a nitrene-rhodium complex which can insert into inert C-H bonds.
now you can do C-H amination with quite high yields and good substrate scope. catalyst turn over is over 500 already.
major player in this area is professor Justin Du Bois.
Perhaps I misunderstood. Of course the intermediate is a metal-nitrene (you can also include copper) but I thought your proposal was intended to overcome the limitation of the carbamate/sulfonamide substrate, thinking of different amides or even amines
ReplyDeletethank you for your reply.
ReplyDeleteThis proposal is intended to find a milder oxidant which can replace PIDA.
It has the potential to expand the substrate scope to other nitrogen source/tolerate more functional groups and increase the turnover of catalyst.