87249-77-2Relevant academic research and scientific papers
Reactions of the thiocarbene complex Cp(CO)2Fe[CH(SMe)]+ with amines
Yu, Yeung S.,Angelici, Robert J.
, p. 1583 - 1589 (1983)
Pyridine (py) reacts with Cp(CO)2Fe[CH(SMe)+, 1, to form the carbene adduct Cp(CO)2Fe[CH-(SMe)(py)]+, 2. With primary (NH2Me, NH2Cy, NH2-i-Pr, and NH2-t-Bu) and secondary (HNMe2, HNEt2) amines and NH3, 1 and 2 react to form the air-stable secondary aminocarbene complexes Cp(CO)2Fe-[CH(NR2)]+. The phosphite-substituted complex Cp(CO)(P(OPh)3)Fe[CH(NEt2)]+ was prepared similarly from Cp(CO)(P(OPh)3)Fe[CH(SMe)]+ and HNEt2. Nonequivalence of the alkyl groups in 1NMR spectra of the complexes containing [CH(NMe2)] and [CH(NEt2)] carbene groups indicates a high barrier to rotation around the C(carbene)-N bond. The Cp(CO)2Fe[CH(NHR)]+ complexes are deprotonated by the bases NaOH-EtOH and NaH to yield the formimidoyl complexes Cp(CO)2Fe[CH(=NR)] which their 1H NMR spectra indicate exist in anti and syn forms. The anti:syn ratio decreases with the R group in the order t-Bu > i-Pr > Cy. Methylation of Cp(CO)2Fe[CH(=NR)] with MeOSO2F gives a mixture of E and Z isomers of Cp(CO)2Fe[CH(NMe-i-Pr)]+. Reactions of the Cp(CO)2Fe[CH(NR2)]+ (NR2 = NHMe, NHCy, NH-t-Bu, and NMe2) complexes with amine (HNR2) lead to removal of the aminocarbene ligand from the metal, thereby giving the formamidinium ion HC(NR2)2+ together with Cp(CO)2FeH. A mechanism involving β-hydrogen transfer from an N atom to the Fe is proposed. The reaction of Cp(CO)2Fe[CH(NHCy)]+ with Me3NO in MeCN, instead of giving products resulting from amine oxide attack at the carbene carbon, gives the stable CO-substituted product Cp(CO)(MeCN)Fe[CH(NHCy)]+, which can also be prepared by photolysis of Cp(CO)2Fe[CH(NHCy)]+ in MeCN. New complexes are characterized by their IR and 1H and 13C NMR spectra.
