The front cover picture illustrates the two possible attacks of a phosphane to an oxirane at either the C or O ring atoms, thus promoting carbene transfer (leading to a phosphorane and a carbonyl unit) or oxygen transfer (which gives rise to an alkene and phosphane oxide), respectively. Mechanistic aspects, substituents effects and the thermodynamic transfer potentials are evaluated. Cover design by Pablo Espinosa Sánchez-Campillo. Background image from benzoix at Freepik. More information can be found in the Research Article by Arturo Espinosa Ferao.