The treatment of Ti(OiPr)(4) with 3-butenylmagnesium chloride generates titanacyclopentene complexes which effectively add to carbonyl compounds and nitriles to afford the 1,4-coupling products with high Z:E selectivities.

Reactions of organo-metal compounds Reactions of organo-metal compounds O 0350Titanacyclopentene Complexes and Their Application as 1,4-Dicarbanion Equivalents. -Treatment of Ti(OiPr) 4 with 3-butenylmagnesium chloride (II) generates a titanacyclopentene complex which effectively adds to carbonyl compounds and nitriles to afford the 1,4-coupling products with high Z:E-selectivity. -(GOEKE*, A.; MERTL, D.; JORK, S.; Chem. Commun. (Cambridge) 2004, 2, 166-167; Richstoff-Forsch., Givaudan AG, CH-8600 Duebendorf, Switz.; Eng.) -M. Paetzel 19-045