Formation of a cyclobutenylidene by cyclo-addition of an alkynyl-ruthenium complex to a cyano(alkynyl)ethene

In contrast to the usual formal [2+2]-cycloaddition reaction, (NC)2CC{CC(SiPri3)}2, containing bulky alkynyl substituents, reacts with Ru(CCPh)(PPh3)2Cp to give the unprecedented cyclobutenylidene complex Ru{C(CN)2C[CC(SiPri3)]CC(SiPri3)CPhC}(PPh3)Cp, formed by addition of one of the CC(SiPri3) groups to the Ru–CCPh moiety and subsequent electronic reorganisation.

In contrast to the usual formal [2+2]-cycloaddition reaction, (NC)2CC{CC(SiPri3)}2 reacts with Ru(CCPh)(PPh3)2Cp to give the unprecedented cyclobutenylidene complex Ru{C(CN)2C[CC(SiPri3)]CC(SiPri3)CPhC}(PPh3)Cp 4, formed by addition of one of the CC(SiPri3) groups to the Ru–CCPh moiety and subsequent electronic reorganisation.Figure optionsDownload as PowerPoint slide