What are the characteristics of click chemistry reaction?

To meet the criteria for being considered click chemistry, the reaction should be straightforwardly modular and adaptable to a variety of substrates. It should consistently yield high product yields while producing only harmless byproducts which can be easily removed using non-chromatographic techniques. Ideally, starting materials and reagents should be readily accessible, and the reaction should occur under mild conditions, such as in non-toxic solvents like water and at room temperature. Additionally, the reaction should exhibit stereo-specificity, although enantioselectivity is not always required. These reactions are also fast, exhibit ease of purification and allow for the specific placement of components (regiospecificity). Lastly, the product should remain stable under physiological conditions.