I don't often write about chemistry these days, but every once in a while I have great fun revisiting things that are so elementary and easy that even I can still remember them. Such as the Diels Alder reaction, which on paper goes like this:
I wrote a news story for Chemistry World on an effort to observe the Diels Alder reaction happening on a surface, using atomic force microscopy (AFM). You can read the story here (open access if you haven't used up your quota of CW stories).
Sadly, the researchers had to make this very simple and elegant reaction quite complicated to achieve this. It made me wonder (after sending off the news piece) if biomolecules might offer a way of positioning a pair of simpler Diels Alder reactants on a surface.
It was long believed that nature didn't have Diels Alder enzymes, so various researchers took up the challenge to fill this gap and produced:
More recently, however, natural Diels-Alderases were discovered, including this one earlier this year.
So there are plenty of biomolecules that by definition recognise and bind Diels Alder reactants. Surely one of them can be persuaded to handle the reaction in a way that is amenable to AFM studies?