Stereospecific 5JHortho,OMe couplings in methoxyindoles,methoxycoumarins, and methoxyflavones

Long‐range coupling constants ⁵J_Hortho,OMe were measured in series of methoxyindoles, methoxycoumarins, and methoxyflavones by the modified J doubling in the frequency domain method. The COSY and NOESY spectra revealed the coupling of the –OMe group with a specific proton at the ortho position and its preferred conformation. Homonuclear ¹H–¹H couplings were confirmed by irradiation of the –OMe signal. Density functional theory calculations of ⁵J_Hortho,OMe using the modified aug‐cc‐pVTZ basis set evidenced that the Fermi contact term shows good agreement with the experimental J values. Accurate chemical shift and coupling constant values followed after iterative quantum mechanical spectral analysis using the PERCH software. Copyright © 2014 John Wiley & Sons, Ltd.     

Efficient Palladium‐Catalyzed Aminocarbonylation of Aryl Iodides Using Palladium Nanoparticles Dispersed on Siliceous Mesocellular Foam

A highly dispersed nanopalladium catalyst supported on mesocellular foam (MCF), was successfully used in the heterogeneous catalysis of aminocarbonylation reactions. During the preliminary evaluation of this catalyst it was discovered that the supported palladium nanoparticles exhibited a “release and catch” effect, meaning that a minor amount of the heterogeneous palladium became soluble and catalyzed the reaction, after which it re‐deposited onto the support.     

New Saccharinato/Ammonia Complexes of Nickel(II) and Zinc(II). A Structural and Spectroscopic Study

Two new saccharinate/NH₃ complexes of composition [Ni(sac)₂(NH₃)₄] and [Zn(sac)₂(NH₃)₂] were obtained and their crystal structures determined by single crystal X‐ray diffractometry. The elongated octahedral Ni^II complex crystallizes in the monoclinic P2₁/c space group with Z = 2 whereas the tetrahedral Zn^II complex is triclinic (space group and Z = 2). For [Ni(sac)₂(NH₃)₄] the magnetic moment and electron absorption spectrum were obtained and discussed. The infrared spectra of both complexes were also recorded and briefly commented.     

Saccharification of native sugar cane bagasse pith by the cross-synergistic action of cellulases fromPenicillium sp. CH-M-001 andA. terreus CH-M-013

Applied Biochemistry and Biotechnology - Filter paper, carboxymethylcellulase, β-glucosidase, and xylanase activities were determined and compared to cellulases originating fromAureobasidium...     

On the stability index of hypersurfaces with constant mean curvature in spheres

Barbosa, do Carmo and Eschenburg characterized the totally umbilical spheres as the only weakly stable compact constant mean curvature hypersurfaces in the Euclidean sphere . In this paper we prove that the weak index of any other compact constant mean curvature hypersurface in n+1 which is not totally umbilical and has constant scalar curvature is greater than or equal to , with equality if and only if is a constant mean curvature Clifford torus with radius .