20611-21-6Relevant articles and documents
Reactivity in Z-Philic Displacements in α-Halogenosulfones
Vernon, Adam,Stirling, Charles J. M.
, p. 1609 - 1610 (1993)
Rates of Z-philic reactions in β-substituted α-bromosulfones have been measured; for displacement-protonation ρ* = 2.9, and isotope fractionation factors close to 2.4 demonstrate extensive C-protonation in the transition structure.
Heptamolybdate: A highly active sulfide oxygenation catalyst
Porter, Ashlin G.,Hu, Hanfeng,Liu, Xuemei,Raghavan, Adharsh,Adhikari, Sarju,Hall, Derrick R.,Thompson, Dylan J.,Liu, Bin,Xia, Yu,Ren, Tong
, p. 11882 - 11887 (2018)
The sulfide oxygenation activities of both heptamolybdate ([Mo7O24]6-, [1]6-) and its peroxo adduct [Mo7O22(O2)2]6- ([2]6-) were examined in this contribution. [Mo7O22(O2)2]6- was prepared in a yield of 65% from (NH4)6[Mo7O24] (1a) upon treatment of 10 equiv. of H2O2 and structurally identified through single crystal X-ray diffraction study. (nBu4N)6[Mo7O22(O2)2] (2b) is an efficient catalyst for the sequential oxygenation of methyl phenyl sulfide (MPS) by H2O2 to the corresponding sulfoxide and subsequently sulfone with a 100% utility of H2O2. Surprisingly, (nBu4N)6[Mo7O24] (1b) is a significantly faster catalyst than 2b for MPS oxygenation under identical conditions. The pseudo-first order kcat constants from initial rate kinetics are 54 M-1 s-1 and 19 M-1 s-1 for 1b and 2b, respectively. Electrospray ionization mass spectrometry (ESI-MS) investigation of 1b under the catalytic reaction conditions revealed that [Mo2O11]2- is likely the main active species in sulfide oxygenation by H2O2.
A sustainable approach towards solventless organic oxidations catalyzed by polymer immobilized Nb(V)-peroxido compounds with H2O2 as oxidant
Ahmed, Kabirun,Gogoi, Sandhya Rani,Islam, Nashreen S.,Saikia, Gangutri,Sultana, Sazida Yasmin,Talukdar, Hiya
, (2021/11/16)
New heterogeneous catalysts comprising of peroxidoniobium(V) complexes immobilized on amino acid grafted cross-linked poly(styrene-divinylbenzene) resin has been developed. Results of FTIR, Raman, NMR, XPS, XRD, EDX, SEM, BET, TGA, and elemental analysis confirmed the successful anchoring of triperoxidoniobium(V), [Nb(O2)3]? species to the host polymer via the pendant amino acid groups. The supported catalysts exhibited excellent performance in epoxidation of styrene and a range of cyclic and terpenic compounds under environmentally acceptable solvent-free condition, with aqueous H2O2 as oxidant. The catalytic protocols provided excellent conversion to the desired epoxide (up to 100%) with selectivity > 99%, TON as high as 1000, and high H2O2 utilization efficiency (92–97%). Moreover, the catalysts efficiently facilitated chemoselective solvent-free oxidation of a variety of thioethers to sulfones at room temperature. Simple operational strategy, easy recyclability for multiple reaction cycles with the consistent activity-selectivity profile are the additional significant attributes of the developed catalytic processes.
{Ti6}/{Ti10} Wheel Cluster Substituted Silicotungstate Aggregates
Li, Hai-Lou,Lian, Chen,Yang, Guo-Yu
, p. 16852 - 16859 (2021/11/13)
Two novel Ti-oxo wheel cluster substituted silicotungstates (STs) [H2N(CH3)2]9H9[Ti6O6(SiW10O37)3]·11H2O (1) and [H2N(CH3)2]16H10[Ti10O11(SiW10O37)2(SiW9O35)2]·14H2O (2) have been made by hydrothermal reactions. The polyoxoanion of 1 is a ring-shaped trimer where a Ti6O6 ({Ti6}) wheel cluster is encapsulated by three divacant [SiW10O37]10- (SiW10O37) fragments. However, 2 is built by two divacant SiW10O37 units and two rare trivacant [SiW9O35]12- (SiW9O35) fragments and further installs an unprecedented Ti10O11 ({Ti10}) double-wheel cluster. To the best of our knowledge, 2 is rare in POM chemistry. Studies on the catalytic oxidation properties reveal that 1 exhibits high catalytic activity toward the oxidation of various sulfides using H2O2 as an oxidant. Furthermore, 1 can be facilely recycled and reused for at least five cycles without obvious loss of catalytic activity.
