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311.
Kamalraj V. Rajendran Lorna KennedyCormac T. O’Connor Enda BerginDeclan G. Gilheany 《Tetrahedron letters》2013
A wide selection of phosphine activators has been screened to improve the selection process in the asymmetric Appel reaction. Of the activators screened, hexachloroacetone (HCA) gave the highest selectivity with excellent yield, but at least one of its by-products, pentachloroacetone (PCA), can become involved in the selection process. In addressing this, a new reaction of phosphines with oxalyl chloride was discovered that can also generate the key intermediate chlorophosphonium salt (CPS), gives better enantioselectivity and possesses significant advantages over other phosphine activators. 相似文献
312.
Niall P. Kenny Dr. Kamalraj V. Rajendran Elizabeth V. Jennings Prof. Declan G. Gilheany 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(42):14210-14214
In contrast to tertiary phosphine oxides, the deoxygenation of aminophosphine oxides is effectively impossible due to the need to break the immensely strong and inert P?O bond in the presence of a relatively weak and more reactive P? N bond. This long‐standing problem in organophosphorus synthesis is solved by use of oxalyl chloride, which chemoselectively cleaves the P?O bond forming a chlorophosphonium salt, leaving the P? N bond(s) intact. Subsequent reduction of the chlorophosphonium salt with sodium borohydride forms the PIII aminophosphine borane adduct. This simple one‐pot procedure was applied with good yields for a wide range of P? N‐containing phosphoryl compounds. The borane product can be easily deprotected to produce the free PIII aminophosphine. Along with no observed P? N bond cleavage, the use of sodium borohydride also permits the presence of ester functional groups in the substrate. The availability of this methodology opens up previously unavailable synthetic options in organophosphorus chemistry, two of which are exemplified. 相似文献
313.
V. Nithyadevi S. P. Rajendran 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):1849-1862
The compounds selenolo(2,3-b)quinoline-2-carboxylic ethyl esters were synthesized in good yields by the reaction of 3-(2-chloro-3-quinolyl)acrylic ethyl esters, with the nucleophilic reagent sodium diselenide in ethanol medium under a nitrogen atmosphere. Cytogenetic studies on human blood leucocytes in vitro were evaluated for some of the synthesized compounds. Most of the synthesized compounds were tested for their antibacterial and antifungal activities. 相似文献
314.
V. Nithyadevi P. Selvi S. P. Rajendran 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):2355-2364
The compounds dihydro selenolo(2,3-b)quinoline-2-carboxylic ethyl esters and 2-selenoxo-1, 2-dihydro-3-carbethoxy ethyl quinolines were synthesized in varying yields upon reacting 3-(2-chloro-3-quinolyl)acrylic methyl esters with the nucleophilic reagent sodium hydrogen selenide in ethanol medium under nitrogen atmosphere. 相似文献
315.
A mathematical model by Hayes et al. [10] of porous catalysts that have non-linear reactions kinetic is discussed. The model involves the non-linear steady-state reaction-diffusion equation. The analytical solution for the concentration of species is obtained using the Adomian decomposition method. Simple and an approximate polynomial expressions for concentration and effectiveness factors are derived for general non-linear Langmiur-Hinshelwood-Haugen-Watson (LHHW) type models which has variety of real rate function. Comparison of the analytical approximation and numerical simulation is also presented. A good agreement between theoretical predictions and numerical results is observed. The concentration and the effectiveness factors are also computed for the limiting cases of LHHW type models. 相似文献
316.
K. Bavya Devi Kulwant Singh N. Rajendran 《Journal of Sol-Gel Science and Technology》2011,59(3):513-520
In this study, the nanoporous zirconium titanate was prepared using sol–gel process and coated over 316L SS implants via dip-coating
technique. XRD patterns of zirconium titanate are crystalline and orthorhombic in structure. FT-IR spectra showed a broad
band between 3,500 and 3,300 cm−1, which was assigned to fundamental stretching vibrations of hydroxyl groups. The set of overlapping peaks in the range of
810–520 cm−1 are related to Zr–O and Zr–O–Ti groups. SEM-EDAX and TEM showed the surface morphology of coated zirconium titanate to be
porous and uniform. Excellent adhesion of the coating to the substrate has been achieved. The contact angle value was found
to be 12°. The coating acts as a barrier layer to the metallic implants and induces the formation of hydroxyapatite layer
on the metal surfaces. These results revealed that the nano zirconium titanate coated 316L SS exhibit higher bioactivity compared
to that of uncoated 316L SS. 相似文献
317.
Aequationes mathematicae - The Hyers-Ulam stability of the iterative equation $$f^n=F$$ for continuous functions F was studied under the assumptions that F is a homeomorphism on its range, and the... 相似文献
318.
L. Govindasamy V. Rajakannan D. Velmurugan S. Shanmuga Sundara Raj T. M. Rajendran R. Venkatesan R. Srinivasan H. K. Fun 《Crystal Research and Technology》2002,37(9):1018-1028
The crystal structure of the title complex has been solved using X‐ray diffraction data.The compound crystallizes from aqueous ethanol solvent in the triclinic system, space group P‐1, with unit cell parameters: a = 8.9532(1), b = 12.7423(3), c = 14.9012(3) Å, α = 73.767(1), β = 75.322(1), γ = 77.496(1)°, Z = 2, V = 1559.4(5) Å3. The trial structure was determined by automated Patterson methods and subsequent difference Fourier techniques using DIRDIF98 and refined to a final R‐factor of 0.064. The copper ion Cu1 adopts a (4+1) square‐pyramidal geometry defined by the tridentate N‐salicylidimine dianions and the neutral monodentate pyridine ligand in the basal plane. The apical position is occupied by a solvent methanol molecule at a distance of 2.341(4) Å. The copper Cu2 adopts a square‐planar geometry. 相似文献