17th International Symposium on Organometallic Chemistry Directed Towards Organic Synthesis (OMCOS), CO, JUL 28-AUG 01, 2013 ; International audience ; Two organometallic catalysis studies are presented. The first one deals with the development of a new catalytic agent based on the mixture of a hydride and an iron salt to trigger efficient radical cyclization processes. In a second line of research, we have shown that the use of chiral anions can outperform chiral ligands in a carbocyclization reaction and a [2 + 2 + 2] cycloaddition.