Synthesis of 1-substituted 2-azaspiro[4.5]deca-6,9-dien-8-ones and 2-azaspiro[4.5]deca-1,6,9-trien-8-ones by condensation of 2,6-dimethylphenol with isobutyraldehyde and nitriles

1-Substituted 3,3,7,9-tetramethyl-2-azaspiro[4.5]deca-6,9-dien-8-ones and 3,3,7,9-tetramethyl-2-azaspiro[4.5]deca-1,6,9-trien-8-ones were synthesized by three-component condensation of 2,6-dimethylphenol with isobutyraldehyde and nitriles in concentrated sulfuric acid.     

Spherical aberration corrected STEM studies of Ge nanodots grown on Si(0 0 1) surfaces with an ultrathin SiO2 coverage

Germanium (Ge) nanodots of about 7 nm size and 2 × 10¹² cm⁻² density were formed on slightly oxidized silicon surfaces. The spherical aberration corrected scanning transmission electron microscopy (Cs-corrected STEM) revealed clearly the size, aspect ratio and interface structures among the nanodots, oxide layers and silicon substrates. In particular, a Ge-rich thin layer underneath SiO₂ layers was found for the first time in these kinds of samples. The elemental distribution through the interface was analyzed by EELS and EDX in the Cs-corrected STEM. The high-resolution Cs-corrected annular dark field (ADF)-STEM image shows clearly the existence of a Ge-rich crystalline layer and its geometry against the oxide layer from the Z-contrast image. A new growth model of the Ge nanodots on slightly oxidized silicon surfaces was proposed.     

Reactions of 1,3,3-trimethyl-3,4-dihydroisoquinolines with polyhaloalkanonitriles

The reactions of 1,3,3-trimethyl-3,4-dihydroisoquinolines with halogenated nitriles afford -aminovinylimines, which undergo acid hydrolysis to form 1-(polyhaloacylmethylene)-3,3-dimethyl-3,4-dihydroisoquinolines.     

Interaction of 1-methylthio-3,3-dimethyl-3,4-dihydroisoquinoline with Β-dicarboxylic acids, Β-dicarbonyl compounds,and their analogs

1-Methylthio-3,3-dimethyl-3,4-dihydroisoquinoline interacts as an electrophile with -dicarbonyl compounds and their analogs to form products in which one or two hydrogen atoms of the -carbonyl compound are replaced by a 3,3-dimethy 1-3,4-dihydroisoquinolyl or 3,3-dimethyl-1,2,3,4-tetrahydroisoquinolylidene fragment.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1651–1654, December 1992.     

Synthesis of substituted bis(3,3-dialkyl-3,4-dihydro-1-isoquinolyl)methanes

Symmetrical and non-symmetrical substituted bis(3,4-dihydro-1-isoquinolyl)methanes were synthesized by fusion of substituted 1-methylthio-3,4-dihydroisoquinolines with 1-methyl-3,4-dihydroisoquinolines and by the Ritter reaction of 1,1-dialkyl-2-arylethanols with 1-cyanomethylidene-1,2,3,4-tetrahydroisoquinoline or malononitrile.     

A facile route to the pentacyclic lamellarin skeleton via Grob reaction between 3-nitro-2-(trifluoromethyl)-2H-chromenes and 1,3,3-trimethyl-3,4-dihydroisoquinolines

The basic structural framework of lamellarin alkaloids, 8,9-dihydro-6H-chromeno[4′,3′:4,5]pyrrolo[2,1-a]isoquinoline derivatives, has been obtained in good yields via Grob reaction between 3-nitro-2-(trifluoromethyl)-2H-chromenes and 1,3,3-trimethyl-3,4-dihydroisoquinolines in refluxing isobutanol. When the reaction was carried out in toluene at room temperature, only Michael adducts, as a mixture of two diastereomers, were isolated.     

Copper(II) chloride complex with bis-1,1′-(3,3-dimethyl-3,4-dihydroisoquinoline): Crystal structure

The copper chloride complex with bis-1,1′-(3,3-dimethyl-3,4-dihydroisoquinoline) (L) was synthesized and characterized by X-ray diffraction and UV/Vis and IR spectroscopy. The structure of the complex [Cu₂L₂Cl₄] is built of centrosymmetric binuclear molecules with a double chlorine bridge. The coordination five-vertex polyhedron of copper is a heavily distorted tetragonal pyramid with a considerably nonplanar base in which the vertices are occupied by chlorine atoms (bridging Cl(1) and Cl(1A) and terminal Cl(2)) and the nitrogen atom N(2); the axial vertex is occupied by N(1). The bond lengths, Cu-N_eq (2.013(1) Å), Cu-N_ax (2.392(2) Å), Cu-Cl_bridge (2.305(1) and 2.342(1)), and Cu-N_term (2.251(1) Å), are markedly different. The coordinated ligand occurs in the cisoid form (the N(1)C(1)C(12)N(2) torsion angle is ?32.6°).