The Wittig reaction in the generation of organometallic compounds containing alkenes as side groups

Abstract

The Wittig reaction has been identified as a viable route to transition metal monomers. It has been used to synthesize {η 5-C 5[C(CH 3)CHR]}Mn(CO) 3 [R  H (68% yield), -CH 3 (60%), -CH 2CH 3 (51%), -CH 2CH 2CH 3 (40%), -C 6H 5 (46%)] from acetylcymantrene and the appropriate phosphorane at room temperature. {η 5C 5H 4[C(CH 3)CHR]}(η 5-C 5H 5)Fe [R  -H (81%), -CH 3 (77%). -CH 2CH 3 (36%), -CH 2CH 2CH 3 (27%) have been prepared from acetylferrocene and phosphorane at room temperature. [η 5-C 5(CHCRR′)H 4](η 5-C 5-H 5)Fe [R,R′ -H,H (79%); -CH 3,H (69%); -CH 2CH 3,H (48%); -CH 2CH 2CH 3,H (49%); -C 6H 5,H (80%); -C(CH 3) 2H,H (73%); -CH 3,CH 3 (67%)] have been produced from formylferrocene and phosphorane in refluxing benzene. E/ Z isomeric ratios were identified for alkenylcymantrenes and are consistent with past Wittig studies. The aldol reaction has been identified as a side route in the Wittig reactions of acetylferrocene and phosphoranes. Carbomethoxyphosphoranes did not produce alkenes at room temperature with nonpolar solvents.