Synthesis of an Arylbromosilylene–Platinum Complex by Using a 1,2-Dibromodisilene As a Silylene Source

Kinetically stabilized 1,2-dibromodisilene, Bbt­(Br)­SiSi­(Br)­Bbt (Bbt = 2,6-bis­[bis­(trimethylsilyl)­methyl]-4-[tris­(trimethylsilyl)­methyl]­phenyl) (<b>2</b>), was treated with [Pt­(PCy₃)₂] to afford the corresponding arylbromosilylene–Pt complex, Bbt­(Br)­SiPt­(PCy₃)₂ (<b>1</b>), as stable orange crystals. The molecular structure of <b>1</b> was elucidated by spectroscopic and X-ray crystallographic analyses. The nature of the Si–Pt bond in <b>1</b> was investigated with the aid of DFT calcualtions

Isolation and Structural Characterization of a Lewis Base-Free Monolithioferrocene

A sterically hindered ferrocenyl lithium derivative was successfully isolated as a stable, crystalline compound without any stabilization by Lewis bases. On the grounds of X-ray crystallography and multinuclear NMR spectroscopy, a dimeric structure was assigned to this monolithioferrocene in the crystalline state and in solution

Syntheses and Structures of Stable 1‑Aminoalumole Derivatives

Reaction of an isolable 1-bromoalumole with LiN­(SiMe₃)₂ in toluene afforded a lithium 1,1-diaminodialumoluide, while in THF the corresponding 1-aminoalumole–THF complex was obtained. These amino-substituted alumole derivatives are characterized by X-ray crystallographic analysis and NMR spectroscopy. The lithium 1,1-diaminoalumoluide and the 1-aminoalumole–THF complex were converted to each other by ligand exchange reactions

Synthesis of a Rhodium Carbonyl Phosphaalkenyl–Phosphido Complex: A Phosphorus Congener of Schiff Base Type N,N′-Chelating Monoanionic Ligands

A monoanionic, bidentate phosphaalkenyl–phosphido ligand was designed, synthesized, and used for the complexation of a rhodium carbonyl fragment. The characterization of the latter revealed delocalized π electrons on the phosphaalkenyl–phosphide moiety. The catalytic activity of this rhodium carbonyl complex has been demonstrated in a hydrosilylation reaction

Syntheses and Structures of Stable 1‑Aminoalumole Derivatives

Reaction of an isolable 1-bromoalumole with LiN­(SiMe₃)₂ in toluene afforded a lithium 1,1-diaminodialumoluide, while in THF the corresponding 1-aminoalumole–THF complex was obtained. These amino-substituted alumole derivatives are characterized by X-ray crystallographic analysis and NMR spectroscopy. The lithium 1,1-diaminoalumoluide and the 1-aminoalumole–THF complex were converted to each other by ligand exchange reactions

Synthesis of a Rhodium Carbonyl Phosphaalkenyl–Phosphido Complex: A Phosphorus Congener of Schiff Base Type N,N′-Chelating Monoanionic Ligands

A monoanionic, bidentate phosphaalkenyl–phosphido ligand was designed, synthesized, and used for the complexation of a rhodium carbonyl fragment. The characterization of the latter revealed delocalized π electrons on the phosphaalkenyl–phosphide moiety. The catalytic activity of this rhodium carbonyl complex has been demonstrated in a hydrosilylation reaction

Expansion of Orifices of Open C₆₀ Derivatives and Formation of an Open C₅₉S Derivative by Reaction with Sulfur

The reaction of a tetraketo-open-cage C₆₀ derivative with elemental sulfur in the presence of tetrakis(dimethylamino)ethylene afforded novel open C₆₀ derivatives containing sulfur atom(s) in the rim of the orifice and the first example of an open C₅₉S derivative. The single crystal X-ray analyses clearly determined these structures and demonstrated that a water molecule was encapsulated inside the cages. The orifice sizes and electronic properties of these fullerene derivatives were revealed

Expansion of Orifices of Open C₆₀ Derivatives and Formation of an Open C₅₉S Derivative by Reaction with Sulfur

The reaction of a tetraketo-open-cage C₆₀ derivative with elemental sulfur in the presence of tetrakis(dimethylamino)ethylene afforded novel open C₆₀ derivatives containing sulfur atom(s) in the rim of the orifice and the first example of an open C₅₉S derivative. The single crystal X-ray analyses clearly determined these structures and demonstrated that a water molecule was encapsulated inside the cages. The orifice sizes and electronic properties of these fullerene derivatives were revealed

Planar Chiral Tetrasubstituted [2.2]Paracyclophane: Optical Resolution and Functionalization

We achieved optical resolution of 4,7,12,15-tetrasubstituted [2.2]­paracyclophane and subsequent transformation to planar chiral building blocks. An optically active propeller-shaped macrocyclic compound containing a planar chiral cyclophane core was synthesized, showing excellent chiroptical properties such as high fluorescence quantum efficiency and a large circularly polarized luminescence dissymmetry factor

El Compostelano : diario independiente: Ano XVIII Número 5198 - 1937 novembro 13

A biomimetic synthesis of zeylanone and zeylanone epoxide, which are natural dimeric naphthoquinones, has been accomplished starting from plumbagin, a natural monomeric naphthoquinone. The key features of our synthesis are cascade intermolecular and intramolecular Michael reactions, followed by epoxidation of the resultant hydroquinone with molecular oxygen