236408-50-7

Upstream product

• 1669-70-1 p-chloro-α-methylstyrene oxide 
• 99-91-2 para-chloroacetophenone 
• 70775-39-2 dimethylsulfoxonium methylide 
• 1712-70-5 1-chloro-4-(1-methylethenyl)-benzene 

Downstream Products

• 1146490-04-1 (2R)-2-(4-chlorophenyl)-2-methyloxetane 

Relevant academic research and scientific papers

Highly enantioselective epoxidation of olefins by H2O2 catalyzed by a non-heme Fe(ii) catalyst of a chiral tetradentate ligand

The chiral tetradentate N4-donor ligand, 1-methyl-2-({(S)-2-[(S)-1-(1-methylbenzimidazol-2-yl methyl)pyrrolidin-2-yl]pyrrolidin-1-yl}methyl) benzimidazole (S,S-PDBzL), based on a chiral dipyrrolidine backbone, has been synthesized and its corresponding Fe(ii) complex has been prepared and characterized. The X-ray structure of the complex reveals that the Fe(ii) ion is in a distorted octahedral coordination environment with two cis-oriented coordination sites occupied by (labile) triflate anions. The ability of the iron complex to catalyze asymmetric epoxidation reactions of olefins with H2O2 was investigated, using 2-cyclohexen-1-one, 2-cyclopenten-1-one, cis-β-methylstyrene, isophorone, chalcones and tetralones as substrates. Different carboxylic acids were used as additives to enhance yields and enantioselectivities, and 2-ethylhexanoic acid was found to give the best results. The catalysis results indicate that the Fe(ii) complex is capable of effecting comparatively high enantioselectivities (>80%) in the epoxidation reactions.

Synergistic interplay of a non-heme iron catalyst and amino acid coligands in H2O2 activation for asymmetric epoxidation of α-alkyl-substituted styrenes

Highly enantioselective epoxidation of α-substituted styrenes with aqueous H2O2 is described by using a chiral iron complex as the catalyst and N-protected amino acids (AAs) as coligands. The amino acids synergistically cooperate with the iron center in promoting an efficient activation of H2O2 to catalyze epoxidation of this challenging class of substrates with good yields and stereoselectivities (up to 97% ee) in short reaction times.

Resolution of 2,2-disubstituted epoxides via biocatalytic azidolysis

A practical procedure for the enzymatic resolution of 2-alkyl-2-aryl- disubstituted epoxides using the Codex HHDH P2E2 enzyme and sodium azide is reported. This method allowed the synthesis of novel regio-and enantioselective 1-azido-2-arylpropan-2-ols in

Accessible sugars as asymmetric olefin epoxidation organocatalysts: Glucosaminide ketones in the synthesis of terminal epoxides

A systematically varied series of conformationally restricted ketones, readily prepared from N-acetyl-d-glucosamine, were tested against representative olefins as asymmetric epoxidation catalysts showing useful selectivities against terminal olefins and, in particular, typically difficult 2,2-disubstituted terminal olefins.

Catalytic asymmetric synthesis of 2,2-disubstituted oxetanes from ketones by using a one-pot sequential addition of sulfur ylide

(Chemical Equation Presented) Better the second time around: The title compounds were synthesized by using a one-pot double methylene transfer catalyzed by a heterobimetallic La/Li complex. Chiral amplification in the second step was the key to obtaining

Catalytic asymmetric synthesis of 2,2-disubstituted terminal epoxides via dimethyloxosulfonium methylide addition to ketones

Catalytic asymmetric Corey-Chaykovsky epoxidation of ketones with dimethyloxosulfonium methylide 2 using an LLB 1a + Ar3P=O complex proceeded smoothly at room temperature, and 2,2-disubstituted terminal epoxides were obtained in high enantioselectivity (91-97%) and yield (>88-99%) from a broad range of methyl ketones with 1-5 mol % catalyst loading. The use of achiral additive Ar3P=O 5i was important to achieve high enantioselectivity. Copyright

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.