In this review we chose to concentrate on the bibliography data from 2013 to
2015 (until February), related to the application of the Inverse Electron Demand Diels-Alder
(IEDDA) reaction to the synthesis of heterocycles, as building blocks for natural products
Moreover, the application of the IEDDA reaction to the recently developed bioorthogonal
ligations (in 2008), using tetrazines moieties as the diene partners, and engineered alkenes or
alkynes as dienophiles, will be detailed. The in vivo applications of the bioorthogonal ligations
are particularly amazing and undoubtedly demonstrate the usefulness of this chemistry.