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Mandan Chidambaram 《Tetrahedron》2007,63(32):7696-7701
Didecyldimethylammonium bromide (DDAB) has been scrutinized in comparison with traditional phase-transfer catalysts in variety of liquid-liquid reactions. It was found to be an exceptionally comprehensive, durable, and highly efficient phase-transfer catalyst (PTC) in a number of representative organic transformations such as C- and N-alkylations, isomerization, esterification, elimination, cyanation, bromination, and oxidation under very mild conditions of temperature and mixing. It was confirmed that DDAB is an exceedingly accessible and concurrently a highly liphophilic phase-transfer catalyst. This unprecedented characteristic renders DDAB to be a multipurpose catalyst that functions effectively both in mass transfer controlled and chemically controlled phase-transfer reactions. 相似文献
34.
Kinetic studies using reaction calorimetry were conducted under synthetically relevant conditions to study the effect of additives in the cyanation of bromobenzene catalyzed by palladium complexes. This work demonstrates that the addition of a catalytic amount of ZnBr(2) facilitates the reaction with an elimination of the induction period observed without additive. This study afforded a qualitative assessment of the effect of water on the rate-limiting step and the apparent reaction order in bromobenzene. 相似文献
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Sp. Chidambaram G. Aravamudan V. Ganesh M. Seshasayee T. A. Sibanova B. V. Merinov V. I. Simonov 《Journal of chemical crystallography》1989,19(3):465-473
The synthesis and crystal structure ofbis(o-phenylenethiourea)selenium(II)-chloride dihydrate, Se(C7H6N2S)2Cl2·2H2O are reported. The compound crystallizes in the monoclinic space group, P21/n, with four molecules per unit cell, the dimensions of which area=10.243(3),b=13.341(4),c=14.273(4) Å,=93.00(3)°,U=1947.76 Å3. The structure was solved by direct methods and refined by full-matrix least-squares toR=0.039 andR
w
=0.040 for 3314 unique reflections. Selenium displays two strong coordinations arising from the two sulfurs, Se-S(1)=2.191(1), Se-S(2)=2.206(1) Å, and S(1)-Se-S(2)=101.0(1)°, and four secondary interactions involving three chlorines and one sulfur. The complex occurs as a dimer with two sets of very weakly interacting bridging pairs S(2), S(2)a; and Cl(2), Cl(2)a, where a denotes the inversion related atom. Lattice stabilization is ensured by the extensive network of hydrogen bonds involving chlorines, water oxygens, and nitrogens of phenylenethiourea ligands. 相似文献
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A combination of pyridinium dichromate/tert-butyl hydroperoxide (1:1) has been found to be an excellent reagent for the highly selective regeneration of ketones from ketoximes. 相似文献
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Gunanathan C Gnanaprakasam B Iron MA Shimon LJ Milstein D 《Journal of the American Chemical Society》2010,132(42):14763-14765
The acridine-based pincer complex 1 exhibits an unprecedented mode of metal-ligand cooperation involving a "long-range" interaction between the distal acridine C9 position and the metal center. Reaction of 1 with H(2)/KOH results in H(2) splitting between the Ru center and C9 with concomitant dearomatization of the acridine moiety. DFT calculations show that this process involves the formation of a Ru dihydride intermediate bearing a bent acridine ligand in which C9 is in close proximity to a hydride ligand followed by through-space hydride transfer. Ammonia induces transfer of a hydride from the Ru center of 1 to C9 of the flexible acridine pincer ligand, forming an unusual dearomatized fac-acridine PNP complex. 相似文献