Synthesis of Symmetric and Unsymmetric 1,1'-Dialkenylferrocenes via Samarium Diiodide Promoted Reactions of 1,1'-Diacetylferrocene with Halides

摘要

Monoalkenylferrocens were prepared from 1,1'-diacetylferrocene and appropriate benzyl bromides by the promotion of samarium diiodide. A practical method for preparation of both symmetric and unsymmetric dialkenylferrocenes was also explored. The reactions were stereoselective to give only (E) double bonds. The unsymmetric dialkenylferrocene bearing electron-donating substituent (e.g.methoxy group) and electron-withdrawing substituent (e.g.cyano group) on different phenyl rings likely exhibits a large noninear optical property.