1801-76-9Relevant academic research and scientific papers
Stereoselective oxidation of linalool with tert-butyl hydroperoxide, catalyzed by a vanadium(V) complex with a chiral terpenoid ligand
Bryliakov,Talsi,Stas'ko,Kholdeeva,Popov,Tkachev
, p. 79 - 88 (2003)
Stereoselective epoxidation of (-)-(R)-linalool by tert-butylhydroperoxide (TBHP) catalyzed by a V complex formed by interaction of [VO(acac)2] or [VO(On-Bu)3] with a new chiral terpenoid ligand was presented. The oxidation of (-)-(R)-linalool with TBHP in the presence of [VO(acac)2] in toluene led to the formation of two diastereomeric monoepoxides, (2S,3R) and (2R,3R), with a poor diastereomeric excess (de 4%, Run 1). The use of CH2Cl2 and CCl4 instead of toluene resulted in the de decrease, while in the presence of MeCN as a solvent, the reaction did not proceed. The oxidation of racemic linalool revealed that a kinetic resolution of the allylic alcohol takes place: at 70% conversion the yield of the (2R,3S)+( 2S,3S) diastromers was 5-fold higher than the yield of the (2S, 2R) + (2R, 3R) diastereomeric pair. Thus, (+)-(S)-linalool oxidation rate was higher as compared to (-)-(R)-linalool. The 51V chemical shift of complex 1 in CH2Cl2 was affected by the presence of TBHP, indicating fast exchange between at least two forms existing in solution. When the concentration of TBHP increased, the 51V signal shifted upfield monotonically.
Transport and electron transfer kinetics of polyoxovanadate-alkoxide clusters
Kosswattaarachchi, Anjula M.,VanGelder, Lauren E.,Nachtigall, Olaf,Hazelnis, Joshua P.,Brennessel, William W.,Matson, Ellen M.,Cook, Timothy R.
, p. A464 - A472 (2019)
A family of four polyoxovanadate-alkoxide (POV-alkoxide) clusters was prepared and electrochemical techniques were used to evaluate diffusion coefficients and electron transport across a range of oxidation states. Synthetic routes were developed to increase the alkyl chain length of the [V6O7(OR)12] cores, increasing R from the previously reported R = CH3, C2H5 to R = C3H7, C4H9. Whereas increasing chain length may enhance solubility, such modifications may also hinder diffusion and electron transfer by shielding the core, thus we experimentally determined these parameters using both cyclic voltammetry and rotating disk voltammetry. Increasing the alkyl chain length of the POV-alkoxide nanostructures from methoxide to butoxide changes the solubility from 0.205 to 0.297 M in acetonitrile. Although some variations in diffusion coefficients and heterogeneous electron transfer rate constants were observed across the suite of oxidation states from species to species, they range from 0.14 × 10-5 cm2/s to 2.24 × 10-5 cm2/s for D0 and 0.56 × 10-3 cm/s to 209.00 × 10-3 cm/s for khet. An increased chain length did not result in lower diffusion coefficients. Thus, we conclude that between C1 and C4 chains, no shielding of the redox core occurs, nor is transport through solution systematically hindered.
