Aldol condensation reactions of [Co(η4-C4Ph4){η5-C5H4C(O)CH3}]

The aldol condensation reaction between [Co(η4-C4Ph4){η5-C5H4C(O)CH3}] and a range of aromatic aldehydes [RCHO] and [RCHCH–CHO] gives a series of α,β-unsaturated ketones [Co(η4-C4Ph4){η5-C5H4C(O)CHCH–R}] and [Co(η4-C4Ph4){η5-C5H4C(O)CHCH–CHCH–R}] (3). The reaction is promoted by various bases: NaH proved to be the most effective whilst nBuLi gave [Co(η4-C4Ph4){η5-C5H4C(OH)(nBu)CH3}] as the major product. NaOH was ineffective, perhaps indicating …