102877-35-0

Upstream product

• 1669-70-1 p-chloro-α-methylstyrene oxide 
• 1712-70-5 1-chloro-4-(1-methylethenyl)-benzene 
• 873-77-8 (4-chlorphenyl)magnesium bromide 
• 116-09-6 hydroxy-2-propanone 
• 191725-56-1 1-chloro-4-(1-methoxyprop-1-en-2-yl)benzene 
• 99-91-2 para-chloroacetophenone 

Downstream Products

• 4445-13-0 2-hydroxy-2-(4-chlorophenyl)propanoic acid 
• 1271738-70-5 C₁₃H₁₅ClO₄ 
• 99-91-2 para-chloroacetophenone 

Relevant academic research and scientific papers

Enhancing selectivity in oxidation catalysis with sol-gel nanocomposites

Valuable organic compounds such as α-hydroxy acids are easily synthesised with relevant selectivity enhancement using a sol-gel hydrophobized nanostructured silica matrix doped with the organocatalyst TEMPO: A materials science based synthetic route which cannot be achieved via classical homogeneous synthesis. The Royal Society of Chemistry 2005.

Photo-Induced Dihydroxylation of Alkenes with Diacetyl, Oxygen, and Water

Herein reported is a photo-induced production of vicinal diols from alkenes under mild reaction conditions. The present dihydroxylation method using diacetyl (= butane-2,3-dione), oxygen, and water dispenses with toxic reagents and intractable waste generation.

Visible light-promoted dihydroxylation of styrenes with water and dioxygen

An efficient visible light promoted metal-free dihydroxylation of styrenes with water and dioxygen has been developed for the construction of vicinal alcohols. The protocol was operationally simple with a broad substrate scope. The mechanistic studies demonstrated that one of the hydroxyl groups came from water and the other one came from molecular oxygen. Additionally, the β-alkyoxy alcohols could also be obtained using a similar strategy.

A simple primary amine catalyst for enantioselective α-hydroxylations and α-fluorinations of branched aldehydes

A new primary amine catalyst for the asymmetric α-hydroxylation and α-fluorination of α-branched aldehydes is described. The products of the title transformations are generated in excellent yields with high enantioselectivities. Both processes can be performed within short reaction times and on gram scale. The similarity in results obtained in both reactions, combined with computational evidence, implies a common basis for stereoinduction and the possibility of a general catalytic mechanism for α-functionalizations. Promising initial results in α-amination and α-chlorination reactions support this hypothesis.

Resolution of diols via catalytic asymmetric acetalization

A highly enantioselective kinetic resolution of diols via asymmetric acetalization has been achieved using a chiral confined imidodiphosphoric acid catalyst. The reaction is highly efficient for the resolution of tertiary alcohols, giving selectivity factors of up to >300. Remarkably, even in cases where the selectivity factors are only moderate, highly enantioenriched diols are obtained via a stereodivergent resolution to diastereomeric acetals.

The nature of the catalytically active species in olefin dioxygenation with PhI(OAc)2: Metal or proton?

Evidence for the protiocatalytic nature of the diacetoxylation of alkenes using PhI(OAc)2 as oxidant is presented. Systematic studies into the catalytic activity in the presence of proton-trapping and metal-complexing agents indicate that protons act as catalysts in the reaction. Using triflic acid as catalyst, the selectivity and reaction rate of the conversion is similar or superior to most efficient metal-based catalysts. Metal cations, such as Pd(II) and Cu(II), may interact with the oxidant in the initiation phase of the catalytic transformation; however, 1 equiv of strong acid is produced in the first cycle which then functions as the active catalyst. Based on a kinetic study as well as in situ mass spectrometry, a mechanistic cycle for the proton-catalyzed reaction, which is consistent with all experimental data presented in this work, is proposed.

Stereospecific decarboxylative allylation of sulfones

Allyl sulfonylacetic esters undergo highly stereospecific, palladium-catalyzed decarboxylative allylation. The reaction allows the stereospecific formation of tertiary homoallylic sulfones in high yield. In contrast to related reactions that proceed at -100 °C and require highly basic preformed organometallics, the decarboxylative coupling described herein occurs under mild nonbasic conditions and requires no stoichiometric additives. Allylation of the intermediate α-sulfonyl anion is more rapid than racemization, leading to a highly enantiospecific process. Density functional theory calculations indicate that the barrier for racemization is 9.9 kcal/mol, so the barrier for allylation must be 9.9 kcal/mol.

NaIO4/LiBr-mediated diastereoselective dihydroxylation of olefins: A catalytic approach to the prevost-woodward reaction

(Chemical Equation Presented) LiBr catalyzes efficiently the dihydroxylation of alkenes to afford syn and anti diols with excellent diastereoselectivity depending upon the use of NaIO4 (30 mol %) or PhI(OAc)2 (1 equiv), respectively, as the oxidants. The oxidation of non-benzylic halides has been achieved for the first time to afford the corresponding diols in excellent yields.

Microbiological transformations 43. Epoxide hydrolases as tools for the synthesis of enantiopure α-methylstyrene oxides: A new and efficient synthesis of (S)-ibuprofen

Biohydrolysis of various α-methylstyrene oxide derivatives, differently substituted at the aromatic ring, was investigated using 10 epoxide hydrolases from different origins. Our results indicate that the enantioselectivity of these biohydrolyses strongly depends on the nature of the enzyme and of the substituent. Using some of these enzymes, this approach allows to prepare these epoxides in high optical purity. The potentiality to perform efficient preparative-scale resolution using such a biocatalyst was illustrated by the four-step synthesis of (S)-ibuprofen, a nonsteroidal antiinflammatory drug and household pain killer, one of the top-ten drugs sold worldwide. Using a combined chemoenzymatic strategy, we were thus able to set up a four-step enantioconvergent procedure allowing for the synthesis of this compound in optically pure form and with a 47% overall yield, including the resolution process, due to a possible recycling of the formed diol via chemical racemisation.