33919-00-5

Upstream product

• 16404-66-3 4-hydroxy-2,4,6-trimethyl-cyclohexa-2,5-dienone 
• 527-60-6 Mesitol 

Downstream Products

• 16404-66-3 4-hydroxy-2,4,6-trimethyl-cyclohexa-2,5-dienone 

Relevant academic research and scientific papers

The Reaction of 4-Hydroperoxy-2,4,6-trimethylcyclohexa-2,5-dienone with Acetaldehyde. Formation of the Bis(peroxyacetal)

The reaction of 4-hydroperoxy-2,4,6-trimethylcyclohexa-2,5-dienone with acetaldehyde using trimethylsilyl trifluoromethanesulfonate as catalyst gives 1,1'-bisdiethyl ether (7) in 70percent yield.The struc

Organophotocatalytic Aerobic Oxygenation of Phenols in a Visible-Light Continuous-Flow Photoreactor

A mild photocatalytic phenol oxygenation enabled by a continuous-flow photoreactor using visible light and pressurized air is described herein. Products for wide-ranging applications, including the synthesis of vitamins, were obtained in high yields by precisely controlling principal process parameters. The reactor design permits low organophotocatalyst loadings to generate singlet oxygen. It is anticipated that the efficient aerobic phenol oxygenation to benzoquinones and p-quinols contributes to sustainable synthesis.

Multigram Synthesis of Trioxanes Enabled by a Supercritical CO2Integrated Flow Process

Photochemical synthesis of highly reactive hydroperoxides and their conversion into useful products, such as 1,2,4-trioxanes, are of wide interest for synthetic organic chemistry and pharmaceutical manufacturing particularly because of their relevance as potential antimalarial and anticancer treatment drugs, for example, Artemisinin. One class of antimalarial drugs is based on 1,2,4-trioxane scaffolds although production of such compounds on a gram scale is challenging due to their instability in oxidizable solvents. Furthermore, current methods employ either solid oxidants, which make continuous processing problematic, or molecular oxygen, requiring long reaction times of up to 48 h. Here, we report a new multigram continuous approach using a custom-built high-pressure sapphire photoreactor to synthesize trioxanes via the dearomatization of para-substituted phenols by photogenerated singlet oxygen in supercritical CO2. CO2 also facilitates mixing with O2 and has lower viscosity, thereby improving penetration into the pores of the solid acid catalyst used for the formation of trioxanes. We show the capabilities of a 5.2 mL reactor to scale up the reaction to 67 g/day. This synthetic approach provides a platform to rapidly access high-value compounds under flow conditions, with high atom efficiencies, excellent yields, short reaction times, and without the need for isolation of hazardous intermediates.

Nature inspired singlet oxygen generation to access α-amino carbonyl compounds: Via 1,2-acyl migration

We have discovered chlorophyll catalyzed 1,2-acyl migration reactions to achieve α-amino carbonyl compounds directly from the enaminones. In general, singlet oxygen is generated during photosynthesis in the photosystem II center. This singlet oxygen can readily react with the unsaturated double bonds present in biomolecules. This reactivity intrigued us to apply this concept towards unsaturated enaminones and others to achieve highly valuable compounds. Indeed, this photosensitizer is very cheap, commercially available, main group metal based and provided excellent efficiency for singlet oxygen mediated chemistry by achieving high turnover number (TON) > 300 with a high turnover frequency (TOF) of 50 h-1. Finally, a combination of DFT calculations and detailed mechanistic experiments provided the exact role of the photosensitizer and clear insights into the reaction.

Kinetics of the oxygenation of unsaturated organics with singlet oxygen generated from H2O2 by a heterogeneous molybdenum catalyst

A heterogeneous catalyst containing MoO42- exchanged on layered double hydroxides (Mo-LDHs) is used to produce 1O 2 from H2O2, and with this dark 1O2, unsaturated hydrocarbons are oxidized in allylic peroxides. The oxidation kinetics are studied in detail and are compared with the kinetics of oxidation by 1O2, formed from H 2O2 by a homogeneous catalyst. A model is proposed for the heterogeneously catalyzed 1O2 generation and peroxide formation. The model divides the reaction suspension in two compartments: (1) the intralamellar and intragranular zones of the LDH catalyst; (2) the bulk solution. The 2-compartment model correctly predicts the oxidant efficiency and peroxide yield for a series of olefin peroxidation reactions. 1O 2 is generated at a high rate by the heterogeneous catalyst, but somewhat more 1O2 is lost by quenching with the heterogeneous catalyst than using the homogeneous catalyst. Quenching occurs mainly as a result of collision with the LDH hydroxyl surface, as is evidenced by using LDH supports containing strong 1O2 deactivators such as Ni2+. A total of 15 organic substrates were peroxidized on a preparative scale using the best Mo-LDH catalyst under optimal conditions.

Oxidative de-aromatization of para-alkyl phenols into para-peroxyquinols and para-quinols mediated by oxone as a source of singlet oxygen

(Chemical Equation Presented) Easy does it: Easily handled and environmentally safe oxone generates singlet oxygen which effects the simple and selective oxidative de-aromatization of para-alkyl phenols 1 into para-peroxyquinols 2 under very mild conditions with good to excellent yields. A one-pot access to para-quinols 3 from 1 is also possible after treatment of the crude reaction mixture with sodium thiosulfate.

Singlet oxygen generation from H2O2/MoO42-: Peroxidation of hydrophobic substrates in pure organic solvents

Seventeen organic solvents are screened as reaction media to conduct the molybdate-catalyzed disproportionation of hydrogen peroxide into singlet molecular oxygen, 1O2 (1Δg). The solvents are investigated by resorting to the detection of the infra-red luminescence of 1O2 at 1270 nm. Preparative peroxidations of representative substrates are carried out in the most efficient ones. The latter are protic and polar and constitute a simpler alternative to the well suited but more intricate microemulsion systems for the peroxidation of hydrophobic substrates with chemically generated 1O2.

Oxidative demethylation of 4-methylphenols to 1,4-benzoquinones with hydrogen peroxide, catalyzed by K10 montmorillonite

2,4,6-Trimethylphenol and pentamethylphenol react with hydrogen peroxide in the presence of K10 montmorillonite (22°C, CCl4, 2 h) to afford, respectively, 2,6-dimethyl-1,4-benzoquinone and 2,3,5,6-tetramethyl-1,4-benzoquinone. 2,6-Di-tert-butyl-4-methylphenol and 4-methylphenol do not react under the same conditions. The mechanism of this reaction is discussed.

PHOTOINDUCED ELECTRON TRANSFER OXIDATION - 1. 9,10-DICYANOANTHRACENE-SENSITIZED PHOTOOXIDATION OF HINDERED PHENOLS.

9,10-Dicyanoanthracene (DCA)-sensitized photooxidation reactions of hindered phenols and catechols (I) proceed via the initial electron transfer from 1 to **1DCA. 4-Hydroperoxy-2,5-cyclohexadien-1-ones and 4-hydroxy-2,5-cyclohexadien-1-ones are obtained from 2,4,6-trialkyl-substituted phenols, and an o-benzoquinone and furanone derivatives are afforded from 3,5-di-t-butylcatechol.