Reactions of cyano(alkynyl)ethenes with some alkynyl- and diynyl-ruthenium complexes

Abstract

Reactions of Ru(C CPh)(PPh 3) 2Cp with (NC) 2C CR 1R 2 (R 1 = H, R 2 = C CSiPr i 3 8; R 1 = R 2 = C CPh 9) have given η 3-butadienyl complexes Ru{η 3-C[ C(CN) 2]CPh CR 1R 2}(PPh 3)Cp ( 11, 12), respectively, by formal [2 + 2]-cycloaddition of the alkynyl and alkene, followed by ring-opening of the resulting cyclobutenyl (not detected) and displacement of a PPh 3 ligand. Deprotection (tbaf) of 11 and subsequent reactions with RuCl(dppe)Cp and AuCl(PPh 3) afforded binuclear derivatives Ru{η 3-C[ C(CN) 2]CPh CHC C[ML n ]}(PPh 3)Cp [ML n = Ru(dppe)Cp 19, Au(PPh 3) 20]. Reactions between 8 and Ru(C CC CR)(PP)Cp [PP = (PPh 3) 2, R = Ph, SiMe 3, SiPr i 3; PP = dppe, R = Ph] gave η 1-dienynyl complexes Ru{C CC[ C(CN) 2]CR CH[C C(SiPr i 3)]}(PP)Cp ( 15– 18), respectively, in reactions not involving phosphine ligand displacement. The phthalodinitrile C 6H(C CSiMe 3)(CN) 2(NH 2)(SiMe 3) 10 was obtained serendipitously from (Me 3SiC C) 2CO and CH 2(CN) 2, as shown by an XRD structure determination. The XRD structures of precursor 7 and adducts 11, 12 and 17 are also reported.