181783-75-5

Upstream product

• 52340-78-0 (R,R)-hydroxybenzoin 
• 616-38-6 carbonic acid dimethyl ester 
• 32315-10-9 bis(trichloromethyl) carbonate 
• 75-44-5 phosgene 
• 503-38-8 trichloromethyl chloroformate 
• 124-38-9 carbon dioxide 
• 1439-07-2 (R,R)-trans-stilbene epoxide 
• 57-13-6 urea 
• 1439-07-2 trans-Stilbene oxide 
• 102-09-0 bis(phenyl) carbonate 

Downstream Products

• 1439-07-2 (R,R)-trans-stilbene epoxide 
• 1439-07-2 (S,S)-trans-stilbene oxide 
• 23190-16-1 (1R,2S)-2-Amino-1,2-diphenylethanol 
• 133522-22-2 (1R,2S)-2-azido-1,2-diphenylethan-1-ol 
• 52340-78-0 (R,R)-hydroxybenzoin 

Relevant academic research and scientific papers

Coupling of Carbon Dioxide with Epoxides Efficiently Catalyzed by Thioether-Triphenolate Bimetallic Iron(III) Complexes: Catalyst Structure–Reactivity Relationship and Mechanistic DFT Study

A series of dinuclear iron(III)Icomplexes supported by thioether-triphenolate ligands have been prepared to attain highly Lewis acidic catalysts. In combination with tetrabutylammonium bromide (TBAB) they are highly active catalysts in the synthesis of cyclic organic carbonates through the coupling of carbon dioxide to epoxides with the highest initial turnover frequencies reported to date for the conversion of propylene oxide to propylene carbonate for iron-based catalysts (5200 h?1; 120 °C, 2 MPa, 1 h). In particular, these complexes are shown to be highly selective catalysts for the coupling of carbon dioxide to internal oxiranes affording the corresponding cyclic carbonates in good yield and with retention of the initial stereochemical configuration. A density functional theory (DFT) investigation provides a rational for the relative high activity found for these Fe(III) complexes, showing the fundamental role of the hemilabile sulfur atom in the ligand skeleton to promote reactivity. Notably, in spite of the dinuclear nature of the catalyst precursor only one metal center is involved in the catalytic cycle. (Figure presented.).

Stereochemical divergence in the formation of organic carbonates derived from internal epoxides

Catalysis of the challenging cycloaddition of carbon dioxide to internal epoxides has been studied using iron (III) amine triphenolate complexes and particular focus has been given to the stereochemical regulation of this process. When pure cis- or trans-2,3-epoxybutane is used as substrate, the stereochemistry of the product can be controlled yielding selectively cis- or trans-cyclic carbonates for both epoxidic substrates. This stereochemical divergence relates to two accessible catalytic pathways leading to either the cis or trans product via two distinct ring-closure steps. The involved mechanism and stereocontrol is a function of the catalyst/co-catalyst loading, and is further influenced by the medium, temperature and catalyst/co-catalyst structure. Other trans-internal epoxides could also be successfully converted into the pure trans-cyclic carbonate products without any loss of stereochemical information.

Diphenyl Carbonate: A Highly Reactive and Green Carbonyl Source for the Synthesis of Cyclic Carbonates

A practical, safe, and highly efficient carbonylation system involving a diphenyl carbonate, an organocatalyst, and various diols is presented herein and produces highly valuable cyclic carbonates. In reactions with a wide range of diols, diphenyl carbonate was activated by bicyclic guanidine 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) as a catalyst, which successfully replaced highly toxic and unstable phosgene or its derivatives while maintaining the desired high reactivity. Moreover, this new system can be used to synthesize sterically demanding cyclic carbonates such as tetrasubstituted pinacol carbonates, which are not accessible via other conventional methods.

A Bimetallic Aluminium(Salphen) Complex for the Synthesis of Cyclic Carbonates from Epoxides and Carbon Dioxide

A bimetallic aluminium(salphen) complex is reported as a sustainable, efficient and inexpensive catalyst for the synthesis of cyclic carbonates from epoxides and carbon dioxide. In the presence of this complex and tetrabutylammonium bromide, terminal and internal epoxides reacted at 50 °C and 10 bar carbon dioxide pressure to afford their corresponding cyclic carbonates in yields of 50–94 % and 30–71 % for terminal and internal cyclic carbonates, respectively. Mechanistic studies using deuterated epoxides and an analogous monometallic aluminium(salphen) chloride complex support a mechanism for catalysis by the bimetallic complex, which involves intramolecular cooperative catalysis between the two aluminium centres.

Chiral Macrocyclic Organocatalysts for Kinetic Resolution of Disubstituted Epoxides with Carbon Dioxide

Among chiral macrocycles 1 synthesized, 1m with the 3,5-bis(trifluoromethyl)phenylethynyl group was the best organocatalyst for the enantioselective synthesis of cyclic carbonates from disubstituted or monosubstituted epoxides and CO2. The X-ray crystal structure of 1m revealed a well-defined chiral cavity with multiple hydrogen-bonding sites that is suitable for the enantioselective activation of epoxides. A catalytic cycle proposed was supported by DFT calculations.

Iron-Catalyzed Synthesis of Five-Membered Cyclic Carbonates from Vicinal Diols: Urea as Sustainable Carbonylation Agent

A new iron-catalyzed synthesis of cyclic carbonates from the corresponding vicinal diols and urea is described. This straightforward transformation allows for the preparation of a variety of five-membered carbonates by employing an inexpensive and environmentally benign iron salt as the catalyst. The use of readily available feedstocks such as urea and polyols makes this a sustainable process. As ammonia is formed as the only stoichiometric byproduct, this process can also be characterized by its high atom economy.

Poly(4-vinylimidazolium)s/diazabicyclo[5.4.0]undec-7-ene/zinc(II) bromide-catalyzed cycloaddition of carbon dioxide to epoxides

Poly(4-vinylimidazolium)s, derived from the self-immobilization of 4-vinylimidazoliums, with diazabicyclo[5.4.0]undec-7-ene (DBU) and zinc bromide (ZnBr2) are used as a highly efficient catalyst for the chemical fixation of carbon dioxide. This catalytic system has been applied for the preparation of cyclic carbonates from terminal epoxides and carbon dioxide. Many functional groups, including chloro, vinyl, ether, and hydroxy groups are well tolerated in the reactions. Moreover, the catalytic system was found to catalyze the conversion of more sterically congested epoxides which are generally considered to be challenging substrates for fabricating the cyclic organic carbonates. In addition, the disubstituted epoxides are found to react with retention of configuration. The polymer precatalyst is easily recovered and reused. A plausible reaction mechanism is proposed.

Remarkably efficient charcoal-promoted ring-closing carbonylations

An efficient, versatile and practical gram-scale preparation of oxazolidinone, imidazolidinone and dioxolanone is achieved. Georg Thieme Verlag Stuttgart.

[(11)C] Carbon monoxide in selenium-mediated synthesis of (11)C-carbamoyl compounds.

Using either amines, amino alcohols, or alcohols in selenium-mediated synthesis with [(11)C]carbon monoxide, 3 ureas, 6 carbamates, and 1 carbonate were labeled. Tetrabutylammonium fluoride ((TBA)F) was discovered to form a soluble and reactive complex with selenium and drastically increase the radiochemical yields. Of the selected carbamoyl compounds, one was a receptor ligand, one was an enzyme inhibitor, and one was a muscular relaxant pharmaceutical. The (11)C-target compounds were obtained in radiochemical yields ranging from low to almost quantitative and with specific radioactivity up to 1300 GBq/micromol. The radiochemical purity of the final products exceeded 98%. In one case, the corresponding (13)C-substituted compound was produced to verify the position of the (11)C-label. In a typical experiment starting with 16.4 GBq [(11)C]carbon monoxide, 7.0 GBq of LC-purified 5-phenyl-1,3-oxazolidin-[2-(11)C]-2-one was obtained within 20 min from start of the carbonylation reaction (84% decay-corrected radiochemical yield). The presented approach is an interesting alternative to the use of [(11)C]phosgene in labeling chemistry.

Induction of cholesteric mesophases by simple cyclic derivatives of p,p'-disubstituted 1,2-diphenylethane-1,2-diols: Importance of shape and polarizability effects

A systematic study of the cholesteric induction in nematic solvents (MBBA and E7) by some cyclic derivatives of unsubstituted and p,p'- disubstituted-1,2-diphenylethane-1,2-diols shows that the values of the twisting power are significantly dependent on t