Coupling of Well‐Established Organotransition Metal Chemistry Donor Groups to Multielectron Ligands

A variety of tailor-made four-electron ligands could contribute to more effective syntheses with transition metal compounds. Examples: on treatment with Ph2PLi and LiC5H4(CH2)2CHLi-pyridyl, (1) gives the ligands (2) and (3), respectively; with PhAsLi2/FeCl2 and pyridyl-CHLi2/FeCl2, compound (1) gives the ansa-ferrocenes (4a) and (4b).