[Nescafe]

Are there different types of click chemistry? I know the main one is a copper (I) based click chemistry, but do people classify staudinger reaction as a click or just a method of ligation?

Nescafe.

[discodermolide]

Are there different types of click chemistry? I know the main one is a copper (I) based click chemistry, but do people classify staudinger reaction as a click or just a method of ligation?

Nescafe.

The Staudinger reaction is a method for producing primary amines form azides and as such is a reduction. The copper based reaction is a cycloaddition.

[Nescafe]

Okay, understood. But are there different types of "click chemistry"?

[discodermolide]

Okay, understood. But are there different types of "click chemistry"?

Not really.

[synthon]

I'm not quite sure what a 'type' of click chemistry would be.  Maybe you could clarify what you are looking for?

I assume that less common examples of click chemistry reactions are what you're looking for, specifically those which don't use copper?  If so, you can find a good summary of click reactions on the related Wikipedia page (and also the wiki page for bioorthogonal chemistry).

http://en.wikipedia.org/wiki/Click_chemistry

http://en.wikipedia.org/wiki/Bioorthogonal_chemistry

[Nescafe]

The answer I was looking for was copper free and copper based click chemistry. I never understood why the strain in cycloocytne,which is used in copper free based click chemistry increases the reactivity. I get that it is favorable to release the strain. But why would such a structure form in the first place when it is so unfavorable to have such a strain in a cyclic system. The bond angles deviate from the preferred 180 of a C-C in cyclooctyl, so obviously it is not happy to have such a strain and would favor to get rid of it, so why would it form in the first place? The reaction is thermodynamically driven? As in the product is much lower in energy than the SM, the activation barrier is low so it is a very favorable exothermic reaction?

Nescafe.

[helenn]

"click" chemistry is often used as a term to describe the copper catalysed azide alkyne Huisgen cycloaddition (CuAAC), but the term "click chemistry" was first used by Sharpless (Angew. Chem. Int. Ed., 2001, pg 2004) to describe reactions which readily create carbon-heteroatom bonds to create combinatorial libraries. The wikipedia page gices and overview of different click reactions.

Copper catalysed Huisgen cycloaddition and the cyclooctyne version and Staudinger Ligation are reactions which have been described as bioorthogonal by Carolyn Bertozzi who has done a lot of work in this area and this may be where you are getting confused.