Organoruthenium(II) complexes formed by insertion reactions of some vinyl compounds and conjugated dienes into a hydrido–ruthenium bond

Abstract

The hydridoruthenium(II) complex [ RuCl(CO) H (PPh₃)₃](1) reacted easily with methyl acrylate and N,N-dimethylacrylamide to give the corresponding insertion products,[[graphic omitted]OMe}Cl(CO)(PPh₃)₂](2a) and [[graphic omitted]NMe₂}Cl(CO)(PPh₃)₂](3), respectively. Similarly, complex (1) reacted with 2-vinylpyridine and 5-ethyl-2-vinylpyridine to afford the C¹,N-chelating organoruthenium(II) complexes, [[graphic omitted]}Cl(CO)(PPh₃)₂](4a) and [[graphic omitted]}Cl(CO)(PPh₃)₂](5) respectively. Complexes (2a) and (4a) reacted with LiBr·H₂O to give the analogous bromo-complexes. The conjugated dienes, penta-1,3-diene, isoprene, and methyl sorbate were treated with (1) to yield the η³-allylic ruthenium(II) complexes, [Ru{η³-R¹C(H)C(R²)CHR³}Cl(CO)(PPh₃)₂][(6) R¹= R³= Me, R²= H; (7) R¹= R²= Me, R³= H; (8) R₁= Et, R²= H, R³= CO₂Me], respectively. On the basis of ¹H and ¹³C-{^lH} n.m.r. data, it has been concluded that the two PPh₃ ligands in (2)–(5) are located trans to each other, whereas those in (6)–(8) are cis.