4540-44-7Relevant academic research and scientific papers
Highly disordering nanoporous frameworks of lanthanide-dicarboxylates for catalysis of CO2 cycloaddition with epoxides
Chiangraeng, Natthiti,Konno, Takumi,Kuwamura, Naoto,Nimmanpipug, Piyarat,Rujiwatra, Apinpus,Thammakan, Supaphorn
, (2021/08/06)
A series of nanoporous [LnIII4(di-nitro-BPDC)4(NO2)3(OH)(H2O)5]·n(methanol) (LnIII ?= ?PrIII, NdIII, SmIII, EuIII, GdIII, PrIII/GdIII and PrIII/EuIII; di-nitro-BPDC2- ?= ?2,2′-dinitrobiphenyl-4,4′-dicarboxylate) was synthesized and characterized. Founded on Lewis acidic LnIII possessing vacant coordination sites and functional groups of di-nitro-BPDC2-, their catalytic activities were evaluated based on the CO2 cycloaddition reactions with epoxides under ambient pressure and solvent-free conditions. Depending on catalytic conditions, satisfying turnover number and turnover frequency of 1106 and 276 h-1, respectively, could be yielded with ≥79(±4)% conversion and 87(±1)% selectivity. The correlation between the catalysis performance and structural factors is proposed on a basis of experimental and computation results. These include the restrained transportation even in the nanoporous framework and crystallographic disorder in the LnIII coordination environment. The excellent robustness of the catalysts, effects of lanthanide contraction, and synergistic activities of the heterometallic PrIII/GdIII and PrIII/EuIII catalysts are also included.
Asymmetric Synthesis of Functionalized trans-Cyclopropoxy Building Block for Grazoprevir
Xu, Feng,Zhong, Yong-Li,Li, Hongming,Qi, Ji,Desmond, Richard,Song, Zhiguo J.,Park, Jeonghan,Wang, Tao,Truppo, Matthew,Humphrey, Guy R.,Ruck, Rebecca T.
supporting information, p. 5880 - 5883 (2017/11/10)
A practical and asymmetric synthesis of a functionalized trans-cyclopropoxy building block for the preparation of the HCV NS3/4a protease inhibitor grazoprevir is reported. Intramolecular SN2 displacement-ring closure, followed by a Baeyer-Villiger oxidation, yields the desired trans-cyclopropanol with full control of diastereoselectivity. A terminal alkyne is then effectively installed using LiNH(CH2)2NEt2. Starting from (S)-epichlorohydrin, the cyclopropoxy building block is prepared in 51% overall yield with >99.8% optical purity without isolation of any intermediates.
Trihaloisocyanuric Acid/Triphenylphosphine: An Efficient System for Regioselective Conversion of Epoxides into Vicinal Halohydrins and Vicinal Dihalides under Mild Conditions
De Andrade, Vitor S. C.,De Mattos, Marcio C. S.
, p. 1381 - 1388 (2016/05/19)
A new synthetic method has been developed for the regioselective conversion of epoxides to vicinal chloro-/bromohydrins and vicinal dihalides by reaction with the system trihaloisocyanuric acid/tri?phenylphosphine in acetonitrile under mild and neutral conditions. The reactions proceed smoothly in high yield at room temperature and at reflux, respectively, over a short time.
1,3,2,4-diazadiphosphetidine-based phosphazane oligomers as source of P(III) atom economy reagents: Conversion of epoxides to vic -haloalcohols, vic -dihalides, and alkenes in the presence of halogen sources
Iranpoor, Nasser,Firouzabadi, Habib,Etemadidavan, Elham
, p. 1165 - 1173 (2014/10/16)
1,3,2,4-Diazadiphosphetidines (P1-P3), as easily prepared, stable, and heterogeneous P(III) compounds, were used for the efficient conversion of epoxides to vic-halohydrins, vic-dihalides, or alkenes in the presence of different halogen sources in CH3CN. Of these phosphazanes, P3 is most suitable and contains 4 phosphorous atoms with the advantage of having greater atom economy and its phosphorus oxide byproduct can be easily separated from the reaction mixture by simple filtration. The nitrogen atoms in this molecule can also act as acid scavengers in the reaction.
Synthesis of Di-, Tri-, and tetrasubstituted oxetanes by rhodium-catalyzed O-H insertion and C-C bond-forming cyclization
Davis, Owen A.,Bull, James A.
supporting information, p. 14230 - 14234 (2015/02/19)
Oxetanes offer exciting potential as structural motifs and intermediates in drug discovery and materials science. Here an efficient strategy for the synthesis of oxetane rings incorporating pendant functional groups is described. A wide variety of oxetane 2,2-dicarboxylates were accessed in high yields, including functionalized 3-/4-aryl-and alkyl-substituted oxetanes and fused oxetane bicycles. Enantioenriched alcohols provided enantioenriched oxetanes with complete retention of configuration. The oxetane products were further derivatized, while the ring was maintained intact, thus highlighting their potential as building blocks for medicinal chemistry.
Mild organic ammonium tribromide-mediated regioselective ring opening of epoxides with alcohols, water, acetic anhydride, and amines under solvent-free reaction conditions
Singhal, Sweety,Jain, Suman L.,Sain, Bir
experimental part, p. 1829 - 1837 (2011/06/19)
Organic ammonium tribromide (OATB), N-methylpyrrolidine-2-one hydrotribromide (MPHT) was found to be an efficient catalyst for the regioselective ring opening of epoxides with various nucleophiles under solvent free conditions. This procedure occurs under neutral and mild reaction conditions with out adding any additive and afforded high yields of products.
Monobromoborane-dimethyl sulfide - A highly promising reagent for the regio- and chemoselective brominative cleavage of terminal epoxides into vicinal bromohydrins
Roy, Chandra D.,Brown, Herbert C.
, p. 139 - 145 (2008/02/11)
Monobromoborane?dimethyl sulfide (BH2Br?SMe2) is a highly regio- and chemoselective reagent useful for the brominative cleavage of the epoxy moiety into bromohydrins in the presence of alkenes, alkynes, ethers, acetals, ketals, and acetonides at 0°C, besides being an excellent hydroborating reagent. Several reactive functional groups, such as chloride, ketones, esters, nitriles, nitros, and thioethers, have been accommodated during such transformations. Although the reduction of acetophenone was completely suppressed at ?25°C, 4-chlorobenzaldehyde still underwent 12?13% reduction of an aldehydic group. CSIRO 2007.
Synthesis of benzodioxepinone analogues via a novel synthetic route with qualitative olfactory evaluation
Drevermann, Britta,Lingham, Anthony R.,Huegel, Helmut M.,Marriott, Philip J.
, p. 1006 - 1027 (2008/02/04)
Marine odorants represent a minor yet diverse class of substances within the fragrance industry, of which 7-methyl-2H-1,5-benzodioxepin-3(4H)-one (1) is commercially known as Calone 1951, a synthetic first in the area of marine-fragrance chemistry. To determine the extent to which the characteristic marine odor of Calone 1951 corresponds to the substitution at the benzo portion of the molecule, a variety of aromatic substituents were incorporated into the benzodioxepinone structure (Scheme 1, Table 3). In light of the difficulty experienced in applying patented literature to deriving the analogues 12-18, particularly those with electron-withdrawing substituents, an alternative synthetic scheme was implemented for the construction of all analogues in favorable yields (Scheme 4, Table 3). Formation of the hydroxy-protected dihalo alkylating agent 24 via epoxide cleavage of epichlorohydrin (Scheme 3) allowed etherification favoring dihalo displacement and subsequent intramolecular ring closure (-→26a-g). THP Deprotection followed by oxidation of the alcohols 27a-g to the ketones 12-18 provided a general pathway to the benzodioxepinone products. The influence of the substituent nature on odor activity revealed a diverse scope of olfactory character (Table 4).
Dimethoxyboron bromide - A new, efficient, regio- and chemoselective reagent for the conversion of terminal epoxides into bromohydrins
Roy, Chandra D.,Brown, Herbert C.
, p. 639 - 641 (2007/10/03)
Dimethoxyboron bromide, (MeO)2BBr, easily prepared in excellent yield from boron tribromide and trimethyl borate, is a new, efficient, regio- and chemoselective reagent useful for the halogenative cleavage of compounds containing epoxy groups into vicinal bromohydrins in the presence of ether, acetal, ketal, N-oxide, and sulfoxide groups, at low temperatures (-78°C).
Highly regioselective ring opening of epoxides and aziridines using (bromodimethyl)sulfonium bromide
Das, Biswanath,Krishnaiah, Maddeboina,Venkateswarlu, Katta
, p. 4457 - 4460 (2007/10/03)
Epoxides and aziridines undergo ring opening efficiently with (bromodimethyl)sulfonium bromide at room temperature to form the corresponding β-bromohydrins and β-bromoamines, respectively. The conversions are highly regioselective and afford the products in excellent yields within a short period of time.
