Neue Synthesen und Reaktionen ungesaettigter Heterotitanacyclen

Article abstract of DOI:10.1016/0022-328X(93)80460-S

Dicarbonyltitanocene reacts chemoselectively with difunctional carbonyl compounds such as 1,2-diketones and 1,4-diketo-2-enes, with α-ketothioketones, α-ketoimines and azodicarbonic esters and -amides to yield the corresponding, mostly new, heterotitanacycles that are capable of a lot of a useful follow-up reactions.These chelate complexes, containing three to four heteroatoms, allow the substitution of the entire titanocene fragment by carbon (formation of vinylenic carbonates and the thia-derivatives of these) or by further heteroatoms like boron or phosphorus(formation of boroles and phosphonic acid derivatives), thus retaining the cyclofunctionality.Alternatively, some of the new chelate complexes can be readily C-C-chain-lengthened via a deprotonating/alkylating sequence, leaving the metallacycle unaffected.