Boron-carbon ligands

The discovery of 1 (1), in 1970, opened a new and fascinating chapter of organometallic chemistry. This cation was the first compound derived from the hypothetical borabenzene 2 and the first complex of a classical boron-carbon ligand. Since then approximately 100 borabenzene derivatives, mainly complexes of 3d metals, have been characterized. Other unsaturated boron-carbon systems have been shown to act as ligands to metals (2). This development has also strongly stimulated the challenging quest for the simple species 2-5. 

The reaction of Co2(CO)8 with 25 is complicated at room temperature, but above 60°C Co(CO)2(C5H5BPh) (11) is obtained as the only complex product (29). Ni(CO)4 reacts with 25 in boiling hexane to give the (cyclopentadienyl)(cyclopentenyl)nickel analog 49 [5(nB) = 24.4 ppm, one broad signal] this complex contains a novel boron-carbon ligand with... 

Heterocyclic ring complexes, and boron-containing rings, 3,42 Hetero-[4+3]-cycloadditions, characteristics, 10, 617 j5-Heterocyclopentadienyl complexes, with platinum, rf-boron-carbon ligands, 8, 663... 

Boron Carbon Ligands Stabilized in Rare Earth Metal Solid State Compounds A Theoretical Approach... 

Another type of ligand, capable of forming multi-hapto interactions with metals, are boron and boron-carbon cage compounds of which in particular the carboranes have been used extensively in organometallic chemistry . The structures in the solid state of a few magnesacarboranes have been determined by X-ray crystallographic studies. 

B3.4 Boron-carbon ring ligands in organometallic synthesis... 

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