cis-Stereochemistry on nucleophilic addition to a cationic η2-alkyne complex, [(η5-C5H5)Fe(CO)2(Ph–CC–Ph)]BF4

Abstract

Treatment of a coordinatively saturated cationic η²-alkyne iron complex [(η⁵-C₅H₅)Fe(CO)₂(Ph–CC-Ph)]BF₄ with various nucleophiles (Nu: O-, S- and N-nucleophiles) does not afford a trans-alkenyl complex but alkenic products with cis-structure, i.e. a cis-alkenyl complex, cis-(η⁵-C₅H₅)(CO)₂Fe–C(Ph)C(Ph)–Nu and/or a metallacycle, (η⁵-C₅H₅)(OC)[graphic omitted])–Nu] or (η⁵C₅H₅)(OC)[graphic omitted]u].