Alternative thinking…….one way to think of deconstructing a heterocycle is to sit down and break the bond forming steps into a spreadsheet of all the known reactions to form them. By now however I am hoping that intuition has crept into the toolbox of things to use…….ask yourself what chemists you know are more intuitive and who are more methodical?

moving on…..Corey Chaykovsky

Following Bill Johnson’s initial work on formation of three membered rings, Corey and Chaykovsky developed the reaction for what it is know today. The scheme below represents the approach: a sulfur ylide (comeon’ man….I love these) and a ketone, imine or an enone.

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Corey Chaykovsky Reaction (CCr)

If you understand anything residual about Prof Corey, you will want to use this from/or for a disconnection. It just so happens that an epoxide attached to an aromatic ring is set up to undergo nucleophilic attack from an amine, and if alpha to that epoxide is a F group, we know that the amine can attack this as well — you see where I am driving at.

In a recent publication on the construction of N-subst indoles (Synthesis 2008), these 3 components were used in a clever way.

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Corey Chayvosky constructed int with amine and elimination of H2O under microwave conditions: ketone, sulfur ylide then amine — indole

Enjoy the reaction!

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