Of late, I have been having a number of discussions about pi-systems with my students. There are many reasons for this surge of interest, too many to mention in one post. This discussion of pushing the boundaries of unusual pi-reactivity reminded me of some really innovative work coming out of Prof. Neil Garg’s lab at UCLA. Neil has pioneered some cool ways of making (and using) indolynes, the distant cousins of benzynes. One of his earlier papers related to this technology appeared back in 2010. I really appreciate this work, which is due to my lab’s long-standing interest in medium sized rings, particularly that of indolactam V, a well-known PKC inhibitor. In Neil’s indolactam synthesis, indolyne intermediates are put to clever use. What you see below is the key step that enables this synthesis. The chemistry involves regioselective addition of an amine nucleophile to the strained indolyne pi-system.