New methods for carbon-carbon (C-C) forming reactions are constantly emerging in the field of organic synthesis. In this review, a brief history followed by recent developments of decarbonylative C-C forming reactions mediated by transition metals is described. Many different substrates are presented and the review is organized by the different carbonyl precursors, such as acyl chlorides, aldehydes, anhydrides, esters and ketones, used in the respective transformations. Furthermore, the broad scope of these reactions is exhibited by the application to several reaction types (e.g. Heck-type reactions, Suzuki cross-coupling type reactions, C-H activation, etc.) as well as a natural product synthesis (e.g. muscroride A). While several examples are provided, this review marks the beginning of a new field that is still in its infancy and for what might be a new approach to achieve highly efficient reactions that come closer to meeting the standards of chemical economies (e.g. atom, redox, step, etc.) and green chemistry. New methods for carbon-carbon (CC) forming reactions are often emerging in the field of organic synthesis. In this review, a brief history followed by recent developments of decarbonylative CC forming reactions mediated by transition metals is described. Many different substrates are presented and the review is organized by the different carbonyl precursors, such as acyl chlorides, aldehydes, anhydrides, esters and ketones, used in the respective transformations. type reactions, Suzuki cross-coupling type reactions, CH activation, etc.) as well as a natural product synthesis (eg muscroride A). While several examples are provided, this review marks the beginning of a new field that is still in its infancy and for what might a a new approach to achieve highly efficient reactions that come closer to meeting the standards of chemical economies (eg atom, redox, s tep, etc.) and green chemistry.