21578-99-4

Upstream product

• 769-57-3 α,β,β-trimethylstyrene 
• 186594-76-3 (1-tert-Butylperoxy-1,2-dimethyl-propyl)-benzene 

Downstream Products

• 29290-99-1 2-methyl-3-phenylbut-1-en-3-ol 
• 25982-72-3 2-methyl-3-phenyl-but-3-en-2-ol 
• 62837-59-6 1,2-dimethyl-1-phenyl-1-propanol 
• 3280-08-8 2-methyl-3-phenyl-butan-2-ol 
• 78805-31-9 2-methyl-3-phenyl-2,3-butanediol 
• 770-85-4 2-methyl-2-phenylbutan-3-one 
• 1231253-32-9 (RS)-2-methyl-3-fluoro-3-phenylbutan-2-ol 

Relevant academic research and scientific papers

Rhenium complex-catalyzed Meinwald rearrangement reactions of oxiranes

The Meinwald rearrangement reaction of oxiranes to the corresponding carbonyl compounds is efficiently catalyzed by the ReBr(CO)5 complex.

Regioselective and Stereospecific Copper-Catalyzed Deoxygenation of Epoxides to Alkenes

Two copper salts (Cu(CF3CO2)2 and IMesCuCl) were identified as earth-abundant, inexpensive, but effective metal catalysts together with diazo malonate for chemo-/regioselective and stereospecific deoxygenation of various epoxides with tolerance of common functional groups (alkene, ketone, ester, p-methoxybenzyl, benzyl, tert-butyldimethylsilyl, and triisopropylsilyl). In particular, the unprecedented regioselectivity allowed for the first time monodeoxygenation of diepoxides to alkenyl epoxides. Density functional theory mechanistic studies showed that the deoxygenation occurred by collapsing the free ylide, unfavoring the possible intuitive pathway via cycloreversion of possible oxetane.

Process for the ruthenium-catalysed epoxidation of olefins by means of hydrogen peroxide

The present invention relates to a process for the epoxidation of olefins using catalysts based on ruthenium complexes in the presence of hydrogen peroxide.

Synthetic, spectral and catalytic activity studies of ruthenium bipyridine and terpyridine complexes: Implications in the mechanism of the ruthenium(pyridine-2,6-bisoxazoline)(pyridine-2,6-dicarboxylate)-catalyzed asymmetric epoxidation of olefins utilizing H2O2

Various Ru(L1)(L2) (1) complexes (L1 = 2,2′-bipyridines, 2,2′:6′,2″-terpyridines, 6-(4S)-4-phenyl-4,5-dihydro-oxazol-2-yl-2,2′-bipyridinyl or 2,2′-bipyridinyl-6-carboxylate; L2 = pyridine-2,6-dicarboxylate, pyridine-2-carboxylate or 2,2′-bipyridinyl-6-carboxylate) have been synthesized (or in situ generated) and tested on epoxidation of olefins utilizing 30% aqueous H2O2. The complexes containing pyridine-2,6-dicarboxylate show extraordinarily high catalytic activity. Based on the stereoselective performance of chiral ruthenium complexes containing non-racemic 2,2′-bipyridines including 6-[(4S)-4-phenyl-4,5-dihydro-oxazol-2-yl]-[2,2′]bipyridinyl new insights on the reaction intermediates and reaction pathway of the ruthenium-catalyzed enantioselective epoxidation are proposed. In addition, a simplified protocol for epoxidation of olefins using urea hydrogen peroxide complex as oxidizing agent has been developed.

Probing competitive enantioselective approach vectors operating in the Jacobsen-Katsuki epoxidation: A kinetic study of methyl-substituted styrenes

This paper describes a study of reactivity and enantioselectivity for a series of methyl-substituted styrenes in the Jacobsen-Katsuki (Mn(salen)-catalyzed) epoxidation reaction. Competition experiments provided kinetic data for the reactivity of the seven possible methyl-substituted styrenes (mono-, di- and trisubstituted) relative to styrene itself, ee values were measured by chiral GC, and absolute configurations were secured by chemical correlation. Of particular interest was the switch in absolute configuration at the benzylic position of the epoxides derived from (Z)- and (E)-α,β-dimethylstyrene, respectively. The results could be rationalized in terms of an approach vector with the phenyl substituent proximal to the salen. As opposed to alkyl groups, a proximal phenyl group has very little effect on the rate of the reaction. Consideration of distal vs proximal approach allows prediction of absolute stereochemistry as a function of alkene substitution pattern. Trisubstituted alkenes with one phenyl group cis to the alkene hydrogen can be identified as a favored substrate class in the title reaction, with both rate and selectivity close to the classic (Z)-β-substituted styrene substrates.

Convenient method for epoxidation of alkenes using aqueous hydrogen peroxide

(Chemical Equation Presented) The complex [Ru(tpy)(pydic)] (1a) is an active catalyst for epoxidation of alkenes by aqueous 30% hydrogen peroxide in tertiary alcohols. The protocol is simple to operate and gives the corresponding epoxides in good to excellent yields. Chiral enantiopure [Ru(tpy*)(pydic) ] complexes have been synthesized and successfully applied in this procedure.

Reactivity and Selectivity in the Oxidation of Styrene Derivatives. IV. Studies on the Oxidation of Substituted β,β-Dimethylstyrenes

The liquid phase oxidation of substituted (p-MeO-, p-Cl-, m-CF3-) 2-aryl-3-methyl-but-2-enes, of 1,1-diphenyl-2-methyl-propene, of 1-ethoxy-2-methyl-1-phenyl-propene and of 9-isopropylidene-fluorene with pure oxygen was investigated in chlorobenzene solution and in presence of cumene and of cumene hydroperoxide in the temperature range 65-125°C. The product yields were determined gaschromatographically. The differences of the activation energies of epoxide formation and the parallel reactions were calculated. They amount to 19-48 kJ/mol. The epoxide selectivity increases with increasing temperature and increasing concentration of olefin. The relative chain propagation constants (kpC=C) were determined by competitive oxidation with cumene. The kpC=C values of substituted β,β-dimethylstyrenes can be correlated by a LFE-relationship with the ionisation energies of the olefins.

Synthesis and reactivity of tert-Butyl-(2-aryl-3-methyl-but-2-yl) peroxides

tert-Butyl-(2-aryl-3-methyl-but-2-yl) peroxides (2a-d) were prepared from t-BuOOH and corresponding 2-aryl-methyl-butan-2-ols (1a-d) (Ar:p-MeO-C6H4 (a); Ph (b); p-Cl-C6H4 (c); m-CF3-C6H4 (d)) and characterized by NMR, MS and elemental analysis. Kinetic data for the thermolysis of 2a-d in cumene as the solvent were determined at 110-140°C and the products analyzed. The rate constants satisfy the Hammett equation with σ giving a ρ-value of -0.73. Oxidation of 2a-d at 80°C gives the corresponding acetophenones 4, epoxides 6 and hydroperoxides 8. The products of the oxidation of 2a-2d were analysed after reduction of the reaction mixtures with LiAlH4. Relative reactivities of the tertiary C-H bonds of peroxides 2 were determined by competitive oxidations. They amount to 0.115-0.275 (with respect to the tertiary C-H bond of cumene). Johann Ambrosius Barth 1997.

On acid-catalysed dehydration of 3-methyl-2-phenylbutan-2-ol

Dehydration of 3-methyl-2-phenylbutan-2-ol (I) using PTS as catalyst under mild conditions yields predominantly the anti-Saytzeff product, 3-methyl-2-phenyl-1-butene (II) which could be freed from its isomer, 2-methyl-3-phenyl-2-butene (III) by Ag+/

Oxidation of Alkenes and Sulphides with a Series of Hydroperoxides having Electron-withdrawing Substituents at the α-Position

The oxidations of alkenes and sulphides with a series of hydroperoxides, α-hydroperoxy-α-methoxyacetophenone (1), α-hydroperoxy-α,α-diphenylacetophenone (2), methyl α-hydroperoxy-α,α-diphenylacetate (3), and α-hydroperoxy-α,α-diphenylacetonitrile (4), were undertaken in a systematic fashion.The data revealed the following. (a) The reactions of electron-rich alkenes (11a and b) with hydroperoxides (1)-(4) are most likely to proceed by a mechanism similar to that with peracids, as do the oxidations of sulphides (5a-e). (b) For the reaction of less reactive alkenes (11f-k) with hydroperoxide (1) in the presence of oxygen, epoxidation by benzoylperoxyl radical contributes to a significantextent.The reaction with hydroperoxide (2) at 60 deg C also seems to proceed by a mechanism involving benzoylperoxyl radical, whereas a molecular epoxidation mechanism is important for the reaction at 30 deg C.Perhaps in accord with this, the reaction of 1,1-disubstituted ethylenes (11c-e) with hydroperoxides (1) and (2) results in the formation of considerable amounts of benzoylated products (13) and (14). (c) For the epoxidation with hydroperoxides (3) and (4), however, a molecular epoxidation process seems to predominate.The exception is the reaction of hydroperoxide (3) with (Z)-2-phenylbut-2-ene and (Z)-stilbene, having very poor reactivity, in which a peroxyl radical, produced by hydrogen abstraction from the hydroperoxide (3), plays an important role in the epoxidation.