I became aware of André Beauchemin’s really interesting Angewandte paper that appeared the other day. André’s lab at the University of Ottawa has been pushing the frontiers of synthesis with some imaginative use of heteroatom-heteroatom bonds as platforms for atom transfer chemistry. The Angewandte paper I refer to deals with novel amphoteric reagents, something that has been of particular interest to my lab for a number of years. Take a look at the hydrazine isocyanate André has developed:
http://onlinelibrary.wiley.com/doi/10.1002/anie.201306379/abstract
The isocyanate molecule shown above is a kinetically amphoteric reagent with the electrophilic carbonyl group of the isocyanate carbon placed several Angstroms away from its nucleophilic hydrazine nitrogen. Due to this constellation of reactive loci in the dense area of space, it is possible to add an amine nucleophile to the carbonyl carbon and quickly follow it up by ring formation “around the corner”. This is accomplished using Andre’s previously reported Cope-type chemistry. The resulting molecules are novel and interesting from the diversity/medicinal chemistry points of view. For me though, it is the amphoteric nature of the centerpiece that is of particular note.
Incidentally, back in 2006, when Ryan Hili and I were thinking about the best way to call our aziridine aldehyde dimers, we really liked the term “amphoteric” due to the origins of the word (“both of two” in Greek). We felt that naming the molecule “bifunctional” would not be descriptive enough. I am not a fan of the term “bifunctional” to begin with… What does it mean? I even get confused with “biweekly”: you think it is unambiguous, but some people use the word to refer to an event taking place once in two weeks, while others – two times a week. I think this is confusing…