Ytterbium cyanide

The high sensitivity of lanthanide reagents to steric factors is also observed in the cyanosilylation reaction of ketones catalyzed by ytterbium cyanide, Yb(CN)3 (Eq. 7) [10], Other reactions, for example epoxide and the aziridine opening by tri-methylsilyl cyanide, TMSCN, are also efficiently catalyzed by Yb(CN)3 [11]. This Yb reagent is not regarded as a Lewis acid but as the active species in these reactions. 

Coordinated cyanide in [Fe(phen)(CN)4], prepared by chlorine oxidation of K2 Fe(phen)(CN)4], can act as a bridging ligand, for example in the complexes [ Fe(phen)(CN)4 2M-(H20)2] 4H20, where M = Mn or Zn, whose structure is of double zigzag chains, and of bipy analogues. There is similar bridging to ytterbium, as in (phen)2Fe //-CN— YbCl3(H20)— NC 2Fe(phen)2, obtained from the reaction of ytterbium trichloride with [Fe(phen)2(CN)2]. ... 

As outlined in CHEC-II(1996) <1996CHEC-II(7)89>, furo[2,3- j-l,3,2-dioxathioles are used mainly in the synthesis of glycosides. Position ia of these systems is susceptible to nucleophilic attack. Ytterbium-catalyzed cyanation of sulfite 53 using NaCN and Yb(OTf)3 in hexamethylphosphoramide (HMPA) at 90 °C produced glycosyl cyanide 54 (Equation 7) <20040L3913>. 

Iodine cleaves one erbium-cyclopentadienyl bond in tricyclopentadienyl erbium with formation of pink dicyclopentadienyl erbium iodide (Maginn et al., 1963), and the tricyclopentadienyl complexes of neodymium and ytterbium are cleaved by hydrogen cyanide with formation of the corresponding dicyclopentadienyl lanthanide cyanide (Kanellakopulos et al., 1974). The colors and some physical data of the cyclopentadienyl rare earth halides and cyanides are given in table 4. 

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