TY - JOUR
T1 - Synthetic and computational studies of thiocarbonyl/σ-organyl coupling reactions
AU - Green, Jennifer C.
AU - Hector, Andrew L.
AU - Hill, Anthony F.
AU - Lin, Sibo
AU - Wilton-Ely, James D.E.T.
PY - 2008/11/10
Y1 - 2008/11/10
N2 - The reactions of a range of coordinatively unsaturated σ-organyl thiocarbonyl complexes with 1,4,7-trithiacyclononane ([9]aneS3) have been investigated, leading in some but not all cases to migratory insertive coupling of thiocarbonyl and σ-organyl ligands. Thus, under ambient conditions, the reaction of [RuR-Cl(CS)(PPh3)2] (R = C(CO2Me)=CHCO2Me, C(C≡CPh)=CHPh, C6H 5) with [9]aneS3 provides σ-organyl complexes [RuR(CS)(PPh3)([9]aneS3)]+. On heating, the species [Ru(C6H5)(CS)(PPh3)([9]aneS 3)]+ converts to the thiobenzoyl complex [Ru(η2-SCPh)(PPh3)([9]aneS3)]+. Similarly the silyl complex [RuCl(SiMe2OEt)-(CS)(PPh 3)2] with [9]aneS3 provides [Ru(SiMe 2OEt)(CS)(PPh3)([9]aneS3)]+. However, the styryl and stilbenyl complexes [Ru(CR=CHPh)Cl(CS)(PPh 3)2] (R = H, Ph) under similar conditions provide dihapto thioacyl derivatives [Ru(η2-SCCR=CHPh)(PPh3)([9] aneS3)]+. The osmium species [Os(CH=CHC6H 4Me-4)Cl(CS)-(BTD)(PPh3)2] (BTD = 2,1,3-benzothiadiazole), however, yields only the nonmigrated product [Os(CH=CHC6-H4Me-4)(CS)(PPh3)([9]aneS 3)]+. Migratory insertion is not induced by other sulfur donor ligands, e.g., Cy3PCS2 (Cy = cyclohexyl) and Na[S2CNMe2], which provide the complexes [Ru(CH=CH 2)(S2CPCy3)-(CS)(PPh3) 2]+ and [Ru(CH=CHPh)(S2CNMe2)(CS) (PPh3)2], respectively. The reactivity of different ligands (R) toward thiocarbonyl migratory insertion in [Ru(R)(CS)(PPh 3)([9]aneS3)]+ was analyzed through density functional theory. The calculated barriers agree qualitatively with experimental observations. In order to determine the electronic effect of substituents on the migrating ligand, a series of hypothetical systems with phenyl ligands varying only in the para-substituent was considered. A general trend that electron-releasing substituents on the migrating ligand promote reaction was observed. Through symmetry-adapted fragment orbital analysis, this phenomenon is determined to correlate well with the energy of the highest occupied π-orbital of the ligand.
AB - The reactions of a range of coordinatively unsaturated σ-organyl thiocarbonyl complexes with 1,4,7-trithiacyclononane ([9]aneS3) have been investigated, leading in some but not all cases to migratory insertive coupling of thiocarbonyl and σ-organyl ligands. Thus, under ambient conditions, the reaction of [RuR-Cl(CS)(PPh3)2] (R = C(CO2Me)=CHCO2Me, C(C≡CPh)=CHPh, C6H 5) with [9]aneS3 provides σ-organyl complexes [RuR(CS)(PPh3)([9]aneS3)]+. On heating, the species [Ru(C6H5)(CS)(PPh3)([9]aneS 3)]+ converts to the thiobenzoyl complex [Ru(η2-SCPh)(PPh3)([9]aneS3)]+. Similarly the silyl complex [RuCl(SiMe2OEt)-(CS)(PPh 3)2] with [9]aneS3 provides [Ru(SiMe 2OEt)(CS)(PPh3)([9]aneS3)]+. However, the styryl and stilbenyl complexes [Ru(CR=CHPh)Cl(CS)(PPh 3)2] (R = H, Ph) under similar conditions provide dihapto thioacyl derivatives [Ru(η2-SCCR=CHPh)(PPh3)([9] aneS3)]+. The osmium species [Os(CH=CHC6H 4Me-4)Cl(CS)-(BTD)(PPh3)2] (BTD = 2,1,3-benzothiadiazole), however, yields only the nonmigrated product [Os(CH=CHC6-H4Me-4)(CS)(PPh3)([9]aneS 3)]+. Migratory insertion is not induced by other sulfur donor ligands, e.g., Cy3PCS2 (Cy = cyclohexyl) and Na[S2CNMe2], which provide the complexes [Ru(CH=CH 2)(S2CPCy3)-(CS)(PPh3) 2]+ and [Ru(CH=CHPh)(S2CNMe2)(CS) (PPh3)2], respectively. The reactivity of different ligands (R) toward thiocarbonyl migratory insertion in [Ru(R)(CS)(PPh 3)([9]aneS3)]+ was analyzed through density functional theory. The calculated barriers agree qualitatively with experimental observations. In order to determine the electronic effect of substituents on the migrating ligand, a series of hypothetical systems with phenyl ligands varying only in the para-substituent was considered. A general trend that electron-releasing substituents on the migrating ligand promote reaction was observed. Through symmetry-adapted fragment orbital analysis, this phenomenon is determined to correlate well with the energy of the highest occupied π-orbital of the ligand.
UR - http://www.scopus.com/inward/record.url?scp=56049124800&partnerID=8YFLogxK
U2 - 10.1021/om800637y
DO - 10.1021/om800637y
M3 - Article
SN - 0276-7333
VL - 27
SP - 5548
EP - 5558
JO - Organometallics
JF - Organometallics
IS - 21
ER -