The preparation of homoallylic alcohols by addition of organometallic allyl compounds to carbonyls is an important strategy in organic chemistry. Allylating organometallic cobalt species can be generated employing stoichiometric quantities of Zn acting as reductant. To avoid the employment of stoichiometric amount of Zn, we have developed an allylation reaction of aromatic and aliphatic aldehydes promoted by photoredox catalysis in the presence of a cobalt complex, and we present herein a full account of our research. In the presence of the abundant CoBr2 (10 mol %), 4,4′‐di‐tert‐butyl‐2,2′‐dipyridyl (dtbbpy, 10 mol %), allyl acetate (3 equiv.), [Ir(dtbbpy)(ppy)2]PF6 (ppy=2‐phenylpyridine, 2 mol %), and N,N‐diisopropylethylamine (4 equiv.), an allylation of aldehydes is taking place, in moderate to good yields. Substrates scope, limitations, and photophysical investigations of this new process are reported.

Despite providing interesting solutions to reduce the number of synthetic steps, to decrease energy consumption or to generate less waste, therefore contributing to a more sustainable way of producing important chemicals, the expansion of the use of homogeneous catalysis in industrial processes is hampered by several drawbacks. One of the most important is the difficulty to recycle the noble metals generating potential high costs and pollution of the synthesized products by metal traces detrimental to their applications. Supporting the metals on abundant and cheap biosourced polymers has recently appeared as an almost ideal solution: They are much easier to recover from the reaction medium and usually maintain high catalytic activity. The present bibliographical review focuses on the development of catalysts based on group 10 transition metals (nickel, palladium, platinum) supported on biopolymers obtained from wood, such as cellulose, hemicellulose, lignin, and their derivatives. The applications of these catalysts in organic synthesis or depollution are also addressed in this review with examples of C-C couplings, oxidation, or hydrogenation reactions.