Anomalous Duff reaction with 2,4-di-tert-butylphenol

Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, p. 2186, September, 1988.     

Steroid compounds of marine sponges. I. Sterols ofEsperiopsis digitata

From extracts of the Far Eastern spongeEsperiopsis digitata, by column chromatography on silica gel we have isolated three fractions of steroid compounds. The fractions isolated have been analyzed with the aid of TLC, GLC-MS, PMR, and¹³C NMR. The least polar fraction (1) had a R_f value identical with that of cholesterol and represents the total free steroids. After argentation column chromatography, 13 components were identified in it, the main one being cholesterol. The more polar fraction (2) consisted of a combination of 3-hydroxychol-5-en-24-al and 3-hydroxy-24-norchol-5-en-23-al. The most polar of the fractions isolated — fraction (3) — consisted of a single component which was identified as cholesta-5,25-diene-3,24-diol.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 740–746, November–December, 1983.     

Cage‐like Copper(II) Silsesquioxanes: Transmetalation Reactions and Structural,Quantum Chemical,and Catalytic Studies

The transmetalation of bimetallic copper–sodium silsesquioxane cages, namely, [(PhSiO_1.5)₁₀(CuO)₂(NaO_0.5)₂] (“Cooling Tower”; 1 ), [(PhSiO_1.5)₁₂(CuO)₄(NaO_0.5)₄] (“Globule”; 2 ), and [(PhSiO_1.5)₆(CuO)₄(NaO_0.5)₄(PhSiO_1.5)₆] (“Sandwich”; 3 ), resulted in the generation of three types of hexanuclear cylinder‐like copper silsesqui‐ oxanes, [(PhSiO_1.5)₁₂(CuO)₆(C₄H₉OH)₂(C₂H₅OH)₆] ( 4 ), [(PhSiO_1.5)₁₂(CuO)₆(C₄H₈O₂)₄(PhCN)₂(MeOH)₄] ( 5 ), and [(PhSiO_1.5)₁₂(CuO)₆(NaCl)(C₄H₈O₂)₁₂(H₂O)₂] ( 6 ). The products show a prominent “solvating system–structure” dependency, as determined by X‐ray diffraction. Topological analysis of cages 1 – 6 was also performed. In addition, DFT theory was used to examine the structures of the Cooling Tower and Cylinder compounds, as well as the spin density distributions. Compounds 1 , 2 , and 5 were applied as catalysts for the direct oxidation of alcohols and amines into the corresponding amides. Compound 6 is an excellent catalyst in the oxidation reactions of benzene and alcohols.     

Remarkable Structural and Electronic Features of the Complex Formed by Trimeric Copper Pyrazolate with Pentaphosphaferrocene

According to spectroscopic (NMR, IR, UV/Vis) study, the interaction of pentaphosphaferrocene [Cp*Fe(η⁵‐P₅)] with trimeric copper pyrazolate [(Cu{3,5‐(CF₃)₂Pz})₃] yields a new compound that is astonishingly stable in solution. Single‐crystal X‐ray analysis reveals unprecedented structural changes in the interacting molecules and the unique type of coordination [Cp*Fe(μ₃‐η⁵:η²,η²‐P₅){Cu(3,5‐(CF₃)₂Pz)}₃]. As a result of the 90° macrocycle folding, the copper atoms are able to behave both as a Lewis acid and as a Lewis base in the interaction with the cyclo‐P₅ ligand.     

Competing ferro- and antiferromagnetic interactions in (manganese,sodium)phenylsilsesquioxane with metal oxide fragments

Magnetic measurements of individual (manganese,sodium)phenylsilsesquioxane containing eight Mn^II ions were performed. The magnetic arrangement of manganese ions in this cage-like compound was investigated. The magnetic moment of the cage molecule equals 21 μ_B (at 300 K), that is a consequence of the mutual antiferromagnetic compensation of four Mn^II ions, whereas the other four Mn^II ions have aligned spins. Hence, this metallasiloxane is a promising compound for the chemical design of molecular nanomagnets. At low temperatures, the antiferromagnetic coupling causes a decrease in the effective magnetic moment (to 16 μ_B at 40 K).