Moisés Vargas-Peñalver

1 Introduction Carbonyl olefination [1] and olefin cross-metathesis [2-13] are two widely used approaches for olefin synthesis (Figure 1A). In theory, cross carbonyl-olefin metathesis [14] (XCOM) accomplishes both of these transformations at the same time, converting a carbonyl to an olefin and a starting olefin into a new one. While the potential applications of such a transformation are numerous, XCOM has remained underdeveloped.