85268-00-4

Upstream product

• 902757-41-9 (+/-)-5-(p-methoxyphenyl)-4-methyl-3-(2-phenylpent-4-en-1-yloxy)-thiazole-2(3H)-thione 
• 75-62-7 Bromotrichloromethane 
• 195213-59-3 4-(p-chlorophenyl)-N-(2-phenyl-4-penten-1-oxy)thiazole-2(3H)-thione 
• 130284-35-4 2-phenyl-pent-4-en-1-ol 

Downstream Products

• 85268-15-1 2-Allyl-2-methyl-4-phenyl-tetrahydro-furan 

Relevant academic research and scientific papers

The (Schiff base)vanadium(v) complex catalyzed oxidation of bromide - A new method for the in situ generation of bromine and its application in the synthesis of functionalized cyclic ethers

(Schiff base)vanadium(v) complexes 5 with tridentate imine auxiliaries served as catalysts for the oxidation of Br with tert-butyl hydroperoxide (TBHP) in nonaqueous solvents. This reaction has been applied for the conversion of substituted 4-penten-1-ols into 5-exo-bromo-cyclized products, including a diastereomerically pure heterocyclic precursor used in a synthesis of the all-trans-configured 2,3,4,5-substituted tetrahydrofuran 2-epi-magnosalicin. Treatment of co-substituted bis(homoallylic) alcohols with the reagent combination of pyHBr, TBHP, and a vanadium(v) catalyst 5 afforded 6-endo-cyclized products, i.e. brominated tetrahydropyrans, as major compounds. The results from 51V NMR, ESI-MS, and supporting reactivity- selectivity studies indicated that the mechanism of the new bromination reaction consists of vanadium-dependent and vanadium-independent steps. A (Schiff base)vanadium(v) compound 5 is required for activation of TBHP via in situ formation of the corresponding tert-butylperoxy complex. This reagent oxidizes Br-, which under the reaction conditions provides Br2 as the active brominating reagent. The molecular bromine generated thus is released into the solution at a steady rate and serves as a reagent for the synthesis of β-brominated cyclic ethers from bis(homoallylic) alcohols in a second, vanadium-independent step. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.

Microwave-assisted generation of alkoxyl radicals and their use in additions, β-fragmentations, and remote functionalizations

Microwave irradiation (2.45 GHz, 300-500 W) of N-(alkoxy)thiazole-2(3H)- thiones in low-absorbing solvents affords alkoxyl radicals, which were identified by (i) spin adduct formation (EPR-spectroscopy) and (ii) fingerprint-type selectivities in intramolecular additions (stereoselective synthesis of disubstituted tetrahydrofurans), β-fragmentations (formation of carbonyl compounds), and C,H-activation of aliphatic subunits, by δ-selective hydrogen atom transfer. C-Radicals formed from oxygen-centered intermediates were trapped either by Bu3SnH, l-cysteine ethyl ester, the reduced form of glutathione (reductive trapping), or by bromine atom donor BrCCl3 (heteroatom functionalization) The results suggest that microwave activation is superior to UV/Vis-photolysis and conductive heating for alkoxyl radical generation from N-(alkoxy)thiazolethiones. It offers by far the shortest reaction times along with the option to reduce the amount of trapping reagent significantly. The Royal Society of Chemistry 2006.