Formation of closo-rhodacarboranes containing η2,η3-(CH2=CHC5H6) ligand in the reaction of μ-dichloro-bis[(η4-norbornadiene)rhodium] with nido-dicarbaundecaborates [K][nido-7-R1-8-R2-7,8-C2B9H10]

The reactions of a complex [(⁴-C₇H₈)RhCl]₂ (C₇H₈ is norbornadiene) with salts of substituted nido-dicarbaundecaborates, [K][nido-7-R¹-8-R²-7,8-C₂B₉H₁₀] (R¹ = R² = H (a); R¹ = R² = Me (b); R¹, R² = 1,2-(CH₂)₂C₆H₄ (c); R¹ = Me, R² = Ph (d)), in CH₂Cl₂ afforded new closo-(²,³-(4-vinylcyclopenten-3-yl))rhodacarboranes. The structures of the compounds were studied by multinuclear NMR spectroscopy. A probable mechanism of the rearrangement of the norbornadiene ligand is discussed.Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1875–1878, September, 2004.     

Migration of the η1:η6-C6H5Cr(CO)3 ligand into the cyclopentadienyl ring during metallation of the η5-C5H5(CO)2Fe η1:η6-C6H5Cr(CO)3 binuclear complex

It was found that the ¹⁶-C₆H₅Cr(CO)₃ ligand migrates into the cyclopentadienyl ring when the ⁵-C₅H₅(CO)₂Fe ¹⁶-C₆H₅Cr(CO)₃ binuclear complex is metallated with BuⁿLi. Under the same conditions, no migration of the phenyl ligand in the ⁵-C₅H₅(CO)₂Fe ¹-C₆H₅ complex was observed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 325–326, February, 1994.     

Synthesis and characterization of complexes η5,η5-(CO)3Mn(C5H4-C5H4)(CO)2Fe-η1,η5-C5H4Mn(CO)3 and μ-(C≡C)[C5H4(CO)2Fe-η1,η5-C5H4Mn(CO)3]2

The complex η⁵,η⁵-(CO)₃Mn(C₅H₄-C₅H₄)(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₃ was synthesized by the reaction of η⁵-Cp(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₃ with BuⁿLi (THF, ?78 °C) and then with anhydrous CuCl₂. The complex μ-(C≡C)[C₅H₄(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₃]₂ was prepared by the reaction of η⁵-IC₅H₄(CO)₂Fe-η¹,η⁵-C₅H₄Mn(CO)₃ with Me₃SnC≡CSnMe₃ (2:1) in the presence of Pd(MeCN)₂Cl₂.     

On the mechanism of C ⇄ N migration of alkoxycarbonyl groups in reactions of pyridinium ylides with isocyanates

New examples of reversible C N migrations of alkoxycarbonyl groups, which occur in the reactions of pyridinium and 3-(diethylcarbamoyl)pyridinium ylides, viz., derivatives of dimethyl and diethyl malonates, with aryl isocyanates were studied. The mechanism of migration of the methoxycarbonyl group from the carbon atom to the nitrogen atom was considered on the basis of quantum-chemical calculations. The product of the primary attack of the isocyanate group by pyridinium ylide was established to be rearranged with low potential barriers to form carbamate without formation of cyclic intermediate compounds.     

Electronic effects in metallocenes

A comparative study of the PMR spectra of isoelectronic ferrocene and cobalticinium salt homologues has been undertaken. With cobalticinium salts the introduction of a positive charge leads to a decrease in the ring proton shielding, while the introduction of alkyl groups has a similar effect on the electronic structure of both the cobalticinium cation and ferrocene. It was found that the introduction of primary and secondary alkyl groups caused proton signal shifts not only in those rings which were directly substituted but also in unsubstituted metallocene rings. However, within the experimental accuracy of the method it was found that the tertiary butyl group has no influence on the proton chemical shifts in the free cyclopentadienyl ring. These results, as well as other chemical data, are explained by assuming that the heteroannular action of aliphatic substituents upon a metallocene system is generally controlled by resonance effects introduced by these groups.     

Synthesis of new organothiophosphorus insectoacaricides containingN-acylated amino acid fragments

Methods for the synthesis ofO-alkylS-(N-acyl-N-alkoxycarbonylalkyl)aminomethyl (methyl)thio- and -dithiophosphonates based on the reaction between alkaline-metal salts ofO-alkyl (methyl)thio- and -dithiophosphonates and N-alkoxycarbonyl-N-chloromethylglycine or --alanine esters and by treatment ofO-alkyl (methyl)dithiophosphonoates andN-acylated amino acids or their esters with paraform in the presence of HCl were developed. The compounds obtained exhibit high insectoacaricide activity and selectivity.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1294–1301, July, 1994.     

Reaction of chloromercuriocobaltacarborane with derivatives of the undecaborate anion

The reactions of the undecaborate anion Cs⁺C₂B₉H₁₂ ^– (1) and exo-nido-ruthenacarborane exo-nido-5,6,10-[Cl(Ph₃P)₂Ru]-5,6,10-(-H)₃-10-H-7,8-C₂B₉H₈ (2) with the 9-chloromercurated cobaltacarborane, viz., 3-(⁵-Cp)-9-ClHg-3,1,2-CoC₂B₉H₁₀ (3), afforded Cs[10-{3"-(⁵-Cp)-3",1",2"-CoC₂B₉H₁₀-9"-Hg}-7,8-C₂B₉H₁₁] (4) and 5,6,10-exo-nido-[Cl(Ph₃P)₂Ru]-5,6,10-(-H)₃-10-{3"-(⁵-Cp)-3",1",2"-CoC₂B₉H₁₀-9"-Hg}-7,8-C₂B₉H₈ (5), respectively. The latter compound exists as two isomers. Compound 5 was prepared also by the reaction of compound 4 with Ru(PPh₃)₃Cl₂.