Synthesen und Charakterisierungen der ersten Tris‐ und Tetrakis(trifluormethyl)palladate(II) und ‐platinate(II), [M(CF3)3(PPh3)]— und [M(CF3)4]2— (M = Pd,Pt)

Syntheses and Characterizations of the First Tris and Tetrakis(trifluoromethyl) Palladates(II) and Platinates(II), [M(CF₃)₃(PPh₃)]^— and [M(CF₃)₄]^2— (M = Pd, Pt) Tris(trifluoromethyl)(triphenylphosphino)palladate(II) and platinate(II), [M(CF₃)₃PPh₃]^—, and the tetrakis(trifluoromethyl)metallates, [M(CF₃)₄]^2— (M = Pd, Pt), are prepared from the reactions of [MCl₂(PPh₃)₂] and Me₃SiCF₃ / [Me₄N]F or [I(CF₃)₂]^— salts in good yields. [Me₄N][M(CF₃)₃(PPh₃)] crystallize isotypically in the orthorhombic space group Pnma (no. 62) with Z = 4. The NMR spectra of the new compounds are described.     

Catalytic asymmetric hydrometallation of cyclobutenes with salicylaldehydes

Chiral, substituted cyclobutanes are common motifs in bioactive compounds and intermediates in organic synthesis but few asymmetric routes for their synthesis are known. Herein we report the Rh-catalyzed asymmetric hydrometallation of a range of meso-cyclobutenes with salicylaldehydes. The ortho-phenolic group promotes hydroacylation and can be used as a handle for subsequent transformations. The reaction proceeds via asymmetric hydrometallation of the weakly activated cyclobutene, followed by a C–C bond forming reductive elimination. A prochiral, spirocyclic cyclobutene undergoes a highly regioselective hydroacylation. This report will likely inspire the development of other asymmetric addition reactions to cyclobutenes via hydrometallation pathways.

Chiral, substituted cyclobutanes are common motifs in bioactive compounds and intermediates in organic synthesis but few asymmetric routes for their synthesis are known.     

Synthesis and Characterization of the 1 : 1-Adducts of In(C6F5)3 with Acetonitrile,Glyme, and DMAP (DMAP = 4-(N,N-dimethylamino)pyridine), and [PNP][In(C6F5)4] (PNP = bis(triphenylphosphinanyliden)immonium) – the Crystal Structure of [PNP][In(C6F5)4]

In(C₆F₅)₃ · CH₃CN and In(C₆F₅)₃ · glyme were synthesized from InCl₃ and Cd(C₆F₅)₂ in CH₃CN or glyme in 43% and 35% yield, respectively. Replacement of CH₃CN or (C₂H₅)₂O by DMAP yielded the corresponding 1 : 1-adduct. [PNP][In(C₆F₅)₄] was best prepared from the corresponding cesium salt which was best synthesized from the reaction of stoichiometric amounts of In(C₆F₅)₃ · CH₃CN, (CH₃)₃ SiC₆F₅ and CsF in good yield. [PNP][In(C₆F₅)₄] crystallizes in the triclinic space group P 1, a = 1104.9(4) pm, b = 1442.4(6) pm, c = 1833.8(8) pm, α = 110.87(2)°, β = 92.04(3)°, γ = 96.55(3)°, Z = 2.     

Silver compounds in synthetic chemistry : Part 4. 4-Tetrafluoropyridyl silver(I), AgC5F4N in redox transmetallations—possibilities and limitations in reactions with group 15 elements

While reactions of AgC₅F₄N with elemental arsenic, antimony, and bismuth proceed selectively yielding E(C₅F₄N)₃ (E = As, Sb, Bi), those with white and red phosphorus remained obscure giving product mixtures of so far unknown stoichiometry. The phosphorus compound was therefore prepared by an alternative route. P(C₅F₄N)₃ and As(C₅F₄N)₃ crystallize isostructurally in the monoclinic space group P2₁/c (no. 14) with four molecules per unit cell. π-π Offset stacking together with edge-face stacking lead to dimeric units which are connected by a second edge-face stacking of nitrogen onto the opposite side of the same tetrafluoropyridyl ring extending the structure into infinite chains.     

1,2,4,5‐Tetrakis(diazidomethyl)benzene

The molecule of the title compound, C₁₀H₆N₂₄, lies on a crystallographic inversion centre located in the middle of the benzene ring. Steric overcrowding by the bulky N₃ groups is avoided by the tendency of four azide entities to be arranged parallel to the benzene ring and the other four azide groups to be arranged alternately above and below the benzene plane in a skeletal C_i symmetry. The compound is of interest for high‐energy research and as a precursor for the synthesis of carbon nanotubes, nanospheres or high‐nitrogen carbon nitrides with great potential for biological and technological applications.