[throwawaymaths]

Fair. This holds a place in my mind as "basically the same as alkyne - azide" since Tetrazzine is "more or less azide" and dbco is "more or less cyclooctyne". More to the point of the thread, I don't think the Tetrazzine/dbco is orthogonal to alkyne-azide -- they will cross-react -- am I wrong about that?

[sdbrown]

Apologies -- tetrazine reacts principally with trans-cyclooctenes. So azide/DBCO would be the orthogonal group. To the best of my knowledge, those two pairs do not cross-react.