Electron-rich C–C multiple bonds such as alkynes, 1 allenes, 2 and 3 and in some cases alkenes 4 can be activated by metal-based catalysts and undergo functionalisation by heteronucleophiles. To facilitate the nucleophilic attack to alkenes, a polarisation of the double bond is often required, for example, by conjugation with a carbonyl function, 5 and 6 another double bond, 7 or an arene. 8 and 9 The lack of reactivity of non-activated olefins towards ...
