Cross Coupling of Acetylenes with Olefins – Formation of η3-Butadienyl and η2-Butadiene Complexes via a Metallacyclobutane Intermediate

✍ Scribed by Christian Slugovc; Kurt Mereiter; Roland Schmid; Karl Kirchner

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 362 KB
• Volume: 1999
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/(sici)1099-0682(199907)1999:7<1141::aid-ejic1141>3.0.co;2-4

✦ Synopsis

Selective coupling of olefins and terminal acetylenes is nation sequence. [Ru(tp)(COD)Cl] and [Ru(tp){η 3 -(P,C,C)-Ph 2 PCH=CHC(Ph)=CH 2 }Cl] were the starting materials shown to be effected in the coordination sphere of Ru II by the successive intermediacy of vinylidene and which were treated with HCϵCR (R = Ph, C 6 H 9 , ferrocenyl, CH 2 Ph, nBu). The η 3 -butadienyl complexes are nucleophilic ruthenacyclobutane complexes. Subsequent deprotonation of one of the β-hydrogen atoms of the latter by NaOEt yields at the enynyl carbon atom reacting readily with the electrophiles H + and I 2 to give the corresponding η 2η 3 -butadienyl complexes, while in the presence of Cl - rearrangement takes place to give neutral η 2 -butadiene butadienyl complexes. X-ray structures of representative products are given. complexes by a β-hydrogen elimination/reductive elimiand terminal acetylenes proceeding via a ruthenacyclobut-[ ]