51036-24-9

Upstream product

• 917-64-6 methyl magnesium iodide 
• 1121-18-2 2-methyl-2-cyclohexen-1-one 
• 60-29-7 diethyl ether 
• 1674-10-8 1,2-dimethylcyclohexene 
• 54683-52-2 1,2-dimethyl-2-cyclohexen-1-yl hydroperoxide 
• 5402-29-9 1,2-dimethylcyclohexanol 
• 75-16-1 methylmagnesium bromide 
• 917-54-4 methyllithium 

Downstream Products

• 23611-14-5 2-methyl-3-methylene-1-cyclohexene 
• 4430-91-5 2,3-dimethyl-cyclohexa-1,3-diene 
• 109364-69-4 2,3-dicyano-5,6-dimethylbicyclo<2.2.2>octa-2,5-diene 
• 1489-54-9 1,2-dimethyl-1,3-cyclohexadiene 

Relevant academic research and scientific papers

Ozonation of Xanthene

The ozonation of xanthene was studied using an oxygen stream.Ozone attacks the methylene group of xanthene via a 1,3-dipolar insertion reaction to give the hydrotrioxide intermediate, followed by a loss of singlet oxygen to form xanthydrol.The ozonation of xanthydrol gave singlet oxygen, water and xanthone accompanied by autoxidation.

Zeolite matrix assisted decomposition of singlet oxygen sensitizers during photooxidation

Thiazine dyes such as thionine, methylene blue and methylene green were exchanged within monovalent cation exchanged Y zeolites. Depending on the water content the dye molecules exist as either monomer (‘dry’) or dimer (‘wet’). The monomeric dye is effect

Amphiphilic Reactions by Means of Exceptionally Bulky Organoaluminum Reagents. Rational Approach for Obtaining Unusual Equatorial, Anti-Cram, and 1,4 Selectivity in Carbonyl Alkylation

Exceptionally bulky, oxygenophilic organoaluminum reagents, methylaluminum bis(2,6-di-tert-4-alkylphenoxide) (MAD and MAT), have been successfully utilized for stereoselective activation of carbonyl moiety.Combination of MAD or MAT with carbon nucleophiles such as organolithiums or Grignard reagents generates a new amphiphilic reaction system in which the alkylation may be interpreted as the nucleophilic addition of a reactive organometallic compound to an electrophilically activated carbonyl substrate in order to account for the regio- and stereochemical consequences.In contrast to the ordinary alkylations, the amphilic alkylation disclosed herein would be categorized into the new, yet unexplored class of alkylation that exhibits high chemoselectivity to carbonyl compounds, and more significantly it allows excellent equatorial and anti-Cram selectivity in carbonyl alkylations, hitherto difficult by the existing methodologies.Further, unusual conjugate addition of organolithium reagents to α,β-unsaturated carbonyl compounds has been accomplished by using the amphiphilic reaction system.

UNUSUAL CONJUGATE ADDITION OF ORGANOLITHIUM REAGENT TO α,β-UNSATURATED KETONE

The conjugate addition of organolithium reagent to α,β-unsaturated ketone has been accomplished with methylaluminum bis(2,6-di-tert-butyl-4-alkylphenoxide) (MAD and MAT).Here combination of alkyllithium and MAD (or MAT) constitutes an amphiphilic system that allows to exhibit unusual selectivity in the alkylation of enones with alkyllithium.

DICYANOANTHRACENE SENSITIZED PHOTO-OXYGENATION OF OLEFINS. ELECTRON TRANSFER AND SINGLET OXYGEN MECHANISMS

Cyanoaromatic sensitizers, in particular 9,10-dicyanoanthracene (DCA), sensitize the photooxygenation of olafins by two distinct mechanisms.In the case of aryl substituted olefins (OL), which react extremely slowly (if at all) with singlet oxygen, the reaction proceeds by way of electron transfer to produce discrete radical ions (DCA-. and OL+.).In the presence of oxygen, this ionic process results, ultimately, in the cleavage of the olefin to carbonyl compounds along with production of some epoxide and other minor byproducts.Aromatic ethers can interfere with this process by reducing the radical cation by electron transfer, resulting in net quenching of the reaction.With simple alkenes the DCA-sensitized reaction takes a different course, producing hydroperoxide products with distributions which are very similar to those obtained with the singlet oxygen ene reaction.Careful study has shown that this reaction does, indeed, proceed by way of singlet oxygen, which is produced by at least two mechanism: (1) enhanced intersystem crossing, in which 1DCA is quenched by interaction with the olefin, leading to a low yield of 3DCA, which subsequently reacts with oxygen to produce singlet oxygen; and (2) direct reaction of 1DCA with oxygen.At limiting high oxygen concentration, this process produces 2 mol of singlet oxygen for each mol of 1DCA quenched; the mechanism involves energy transfer to produce 3DCA and 1 mol of singlet oxygen; the 3DCA reacts again with oxygen to produce a second mol of singlet oxygen.The complex kinetic behaviour of simple olefins in the presence of DCA can be satisfactorily rationalized by these mechanisms.

Methyl-Substituted Poly(vinylnaphthalene) as a Reversible Singlet Oxygen Carrier

Methyl-substituted poly(vinylnaphthalenes) (5a-c) were prepared by radical polymerization of the corresponding vinylnaphthalenes 4a-c.Polymers 5a and 5b have been shown to bind and release singlet molecular oxygen (1O2) reversibly at temperatures between 0 and 35 deg C.Methylene blue sensitized photooxygenation of polymers 5 at 0 deg C produced the corresponding polymer endoperoxides 6 in nearly quantitatve yields.Generation of 1O2 from the thermolysis of polymer endoperoxide 6b at 35 deg C was confirmed by trapping experiments using typical 1O2 acceptors.Kinetic parameters for the thermolyses of 6a and 6b were compared with those for the corresponding monomer endoperoxides.The yield of 1O2 generated from polymer 6b was determined to be as high as 66 +/- 5percent.The synthetic utility of these polymeric endoperoxides as a 1O2 source has been demonstrated in the oxidation of a series of representative substrates.Advantages of using these polymer 1O2 sources are the following: (1) the mild condition for generation of 1O2, (2) utility in nonsolvent systems, and (3) easy removal and resue.

MECHANISTIC STUDY ON THE PHOTO-OXIDATION OF α-DIKETONES. INTERACTION OF TRIPLET α-DIKETONES WITH OXYGEN

The mechanism for photo-oxidation of α-diketones in the presence of olefins has been studied, focusing on the interaction of triplet diketones with O2.Two types of reactions occur competitively.One is the formation of 1O2 by energy transfer to O2 and the other is the addition of O2 to triplet diketone, which yields acylperoxy radicals leading to the radical epoxidation of olefins.Ratios of the two reactions were determined from the yields of 1O2 products and epoxides.For most diketones, quantum yields for 1O2 formation were considerably high, in the range 0.3-0.8; but the yields for epoxides were in a wider range of 0.001-0.5.While the ratios of 1O2 formation and O2 addition to triplet diketones ranged from 29:71 for biacetyl to 1:99 for mesitil, the ratios remained constant by changing solvents or temperature.The latter O2 addition reaction decreased in the order of MeCOCOMe > PhCOCOMe > PhCOCOPh but the effect of m- and p-substituents on benzils was not significant, indicating the addition of O2 as a neutral biradical.In exceptional cases, the O2 addition was not effective for sterically inaccessible mesitil and some cyclic α-diketones.The mechanism of 1O2 formation was discussed in comparison to other carbonyl compounds.

PHOTOCHEMICAL GENERATION OF SINGLET OXYGEN ON NON-TRANSITION-METAL OXIDE SURFACES

Irradiation of the non-transition-metal oxide powders silica gel, aluminium oxide and magnesium oxide in the presence of oxygen results in the formation of singlet oxygen (1O2).Two specific chemical traps were used to detect 1O2: 1,2-dimethylcyclohexene and geminally deuterated 2H6>-2,3-dimethylbut-2-ene.Both compounds gave product distributions characteristic of singlet-oxygen reactions when irradiated on the metal oxide surfaces.These results support previous suggestions that singlet oxygen is formed through an energy-transfer process involving oxygen and excitons on the metal oxide surface.Under the same reaction conditions TiO2 showed no production of 1O2.

CHEMISTRY OF SINGLET OXYGEN. 47. 9,10-DICYANOANTHRACENE-SENSITIZED PHOTOOXYGENATION OF ALKYL-SUBSTITUTED OLEFINS.

9,10-Dicyanoanthracene (DCA) sensitizes the photooxygenation of 1-methylcyclohexene, 1,2-dimethylcyclohexene, and cholesterol in acetonitrile and benzene. For all three olefins, the products are the same as those formed by reaction with singlet oxygen. Th