Day: November 23, 2022

Alame, Mohamad published the artcileExtensive re-investigations of pressure effects in rhodium-catalyzed asymmetric hydrogenations, COA of Formula: C38H24F4O4P2, the publication is Advanced Synthesis & Catalysis (2008), 350(6), 898-908, database is CAplus.

The catalytic hydrogenation of three prochiral substrates Me Z-α-acetamidocinnamate (MAC), Me 2-acetamidoacrylate (M-Acrylate) and Et 4-methyl-3-acetamido-2-propanoate (E-EMAP) with rhodium precursors complexed with chiral diphosphines is reported at 1-30 bar hydrogen pressure. A library of 56 chiral diphosphines, including 23 BINAP derivatives, 7 JOSIPHOS, 5 BIPHEP, 3 DUPHOS derivatives, and 18 other ligands, was used. While it was generally accepted that high hydrogen pressure would result in lower ees, it is now demonstrated on a statistical basis that an equivalent distribution between beneficial and detrimental pressure effects on ee prevails and that the hydrogen pressure effect on enantioselectivity is not an isolated phenomenon since more than 33% of the reaction systems studied are strongly affected. In some case, the enantioselectivity can be improved up to 97% just by applying a higher hydrogen pressure. Extension of these conclusions to other non-chiral reagents is proposed.

Advanced Synthesis & Catalysis published new progress about 503538-69-0. 503538-69-0 belongs to dioxole, auxiliary class (Atropisomeric Bisphosphine Ligands, name is (R)-5,5′-Bis(diphenylphosphino)-2,2,2′,2′-tetrafluoro-4,4′-bi-1,3-benzodioxole, and the molecular formula is C38H24F4O4P2, COA of Formula: C38H24F4O4P2.

Referemce:
https://en.wikipedia.org/wiki/1,3-Benzodioxole,
Dioxole | C3H4O2 – PubChem

Menard, Frederic published the artcileLigand-Controlled Selectivity in the Desymmetrization of meso Cyclopenten-1,4-diols via Rhodium(I)-Catalyzed Addition of Arylboronic Acids, SDS of cas: 503538-69-0, the publication is Journal of Organic Chemistry (2010), 75(12), 4056-4068, database is CAplus and MEDLINE.

A highly enantioselective desymmetrization of meso cyclopent-2-ene-1,4-diethyl dicarbonates has been developed using a Rh-catalyzed asym. allylic substitution. Depending on the type of ligand used, each of two regioisomeric products can be obtained in good yield and excellent enantioselectivity. Under rhodium(I) catalysis, bisphosphine P-Phos ligands form trans-1,2-arylcyclopentenols as the major product, whereas Segphos ligands lead predominantly to trans-1,4-arylcyclopentenols.

Journal of Organic Chemistry published new progress about 503538-69-0. 503538-69-0 belongs to dioxole, auxiliary class (Atropisomeric Bisphosphine Ligands, name is (R)-5,5′-Bis(diphenylphosphino)-2,2,2′,2′-tetrafluoro-4,4′-bi-1,3-benzodioxole, and the molecular formula is C38H24F4O4P2, SDS of cas: 503538-69-0.

Referemce:
https://en.wikipedia.org/wiki/1,3-Benzodioxole,
Dioxole | C3H4O2 – PubChem

Fasi, Andras published the artcileThe ring opening and oligomerization reactions of an epoxide and an episulfide on aluminosilicates in the liquid phase, Formula: C6H12O2, the publication is Central European Journal of Chemistry (2005), 3(2), 230-244, database is CAplus.

The ring opening reactions of propylene oxide (methyloxirane) or ethylene sulfide (thiirane) were studied in the liquid phase over HZSM-5, HY-FAU or AlMCM-41 at 363 K or 423 K and under 1 or 20 bar pressure in a batch reactor. The proportion of these routes were identified: (i) single C-O scission providing non-cyclic products, (ii) double C-O cleavage leading to the loss of the heteroatom, (iii) oligomerization resulting in cyclic dimers and the trimer of thiirane and a non-cyclic dimer of methyloxirane. The reaction pathway depended on the conditions and the solid acids used. Findings are compared to those in the gas phase over the same solid acids. Transformation mechanisms are also suggested.

Central European Journal of Chemistry published new progress about 1193-11-9. 1193-11-9 belongs to dioxole, auxiliary class Dioxolanes, name is 2,2,4-Trimethyl-1,3-dioxolane, and the molecular formula is C6H12O2, Formula: C6H12O2.

Referemce:
https://en.wikipedia.org/wiki/1,3-Benzodioxole,
Dioxole | C3H4O2 – PubChem

Fasi, Andras published the artcileRing-Opening and Dimerization Reactions of Methyl- and Dimethyloxiranes on HZSM-5 and CuZSM-5 Zeolites, COA of Formula: C6H12O2, the publication is Journal of Catalysis (1999), 188(2), 385-392, database is CAplus.

Ring-opening and dimerization reactions of methyloxirane and cis- and trans-2,3-dimethyloxirane were studied on CuZSM-5, prepared by various methods, and HZSM-5 zeolites in a closed static recirculation reactor at 363 K in a reductive atm. On these materials two main reaction types, ring-opening and dimerization, could be observed For methyloxirane the major transformation pathways were ring opening and dimerization, producing various dioxolane and dioxane derivatives In addition to these routes 2,3-dimethyloxiranes underwent deoxygenation and rearrangement. The activities and selectivities of the transformations toward these pathways were found to be significantly different depending on the stereochem. of the substrates as well as the nature of the catalysts. Suggestions for the active sites and transformation mechanisms are also offered. (c) 1999 Academic Press.

Journal of Catalysis published new progress about 1193-11-9. 1193-11-9 belongs to dioxole, auxiliary class Dioxolanes, name is 2,2,4-Trimethyl-1,3-dioxolane, and the molecular formula is C6H12O2, COA of Formula: C6H12O2.

Referemce:
https://en.wikipedia.org/wiki/1,3-Benzodioxole,
Dioxole | C3H4O2 – PubChem

Fasi, A. published the artcileRing opening reactions of methyloxirane over DZSM-5 and DAlMCM-41 molecular sieves – a mechanistic study, Product Details of C6H12O2, the publication is Studies in Surface Science and Catalysis (2001), 3678-3685, database is CAplus.

The ring opening reactions of methyloxirane on DZSM-5 and DAlMCM-41 aluminosilicates were studied in a pulse microreactor at 363 K. Deuterium distribution in the products was monitored Single C-O scission as well as dimerization occurred on both mol. sieves. In these reactions Bronsted and Lewis sites were involved Deuterium distribution revealed details of transformation pathways. It was found the main reaction channel, where deuterium exchange does not occur, involves exclusively the Lewis sites at the potential exchange sites. For deuterium exchange to occur during ring opening at least one Bronsted site is necessary. For dimerization when deuterium exchange takes place many active site combinations may be envisaged, however, for the formation of the dioxolane derivatives two neighboring Bronsted-Lewis site pairs, while for the formation of dioxane derivatives the interplay of one Bronsted-Lewis acid pair and a Lewis-Lewis acid pair seem to be the most advantageous.

Studies in Surface Science and Catalysis published new progress about 1193-11-9. 1193-11-9 belongs to dioxole, auxiliary class Dioxolanes, name is 2,2,4-Trimethyl-1,3-dioxolane, and the molecular formula is C6H12O2, Product Details of C6H12O2.

Referemce:
https://en.wikipedia.org/wiki/1,3-Benzodioxole,
Dioxole | C3H4O2 – PubChem

Cirkva, Vladimir published the artcileRadical addition reactions of fluorinated species. Part 7. Highly selective two-step synthesis of 1-(polyfluoroalkyl)ethane-1,2-diols; regioselectivity of the additions of methylated 1,3-dioxolanes to perfluoroolefins, Computed Properties of 1193-11-9, the publication is Journal of Fluorine Chemistry (1999), 94(2), 141-156, database is CAplus.

The two-step synthesis of the diols is based on the radical addition of 2,2-dimethyl-1,3-dioxolane, a protected ethane-1,2-diol, to perfluoroalk-1-enes R_F-CF:CF₂ (R_F = CF₃, C₉F₁₉) and perfluoro[trifluorovinyl (poly)ethers] R_FO-CF:CF₂ (R_F = C₃F₇, C₃F₇O[CF(CF₃)CF₂], CF₃(OCF₂CF₂)₄) with preparative yields above 90% in each step. The additions were initiated photochem. or by dibenzoyl peroxide and were completely chemoselective and almost completely regioselective. 4-Fluoroalkylated dioxolanes obtained, e.g., I, were deprotected by acid methanolysis to afford 1-polyfluoroalkylethane-1,2-diols, e.g., HOCH₃CH(OH)CF₂CHFCF₃. 1,3-Dioxolane or 2,2,4-trimethyl-1,3-dioxolane reacted at two centers to yield regioisomeric mixtures of fluoroalkylated dioxolanes. The factors influencing fluoroolefin and dioxolane regioselectivity are discussed.

Journal of Fluorine Chemistry published new progress about 1193-11-9. 1193-11-9 belongs to dioxole, auxiliary class Dioxolanes, name is 2,2,4-Trimethyl-1,3-dioxolane, and the molecular formula is C6H12O2, Computed Properties of 1193-11-9.

Referemce:
https://en.wikipedia.org/wiki/1,3-Benzodioxole,
Dioxole | C3H4O2 – PubChem

Zhong, Shaofeng published the artcilePhosphorus promoted SO₄^2-/TiO₂ solid acid catalyst for acetalization reaction, Synthetic Route of 177-10-6, the publication is Journal of the Chilean Chemical Society (2015), 60(3), 3005-3008, database is CAplus.

A novel phosphorus modified SO₄^2-/TiO₂ catalyst was synthesized by a facile coprecipitation method, followed by calcination. The catalytic performance of this novel solid acid was evaluated by acetalization. The results showed that the phosphorus was very efficient to enhance the catalytic activity of SO₄^2-/TiO₂. The solid acid owned high activity for the acetalization with the yields over 90%. Moreover, the solid acid could be reused for six times without loss of initial catalytic activities.

Journal of the Chilean Chemical Society published new progress about 177-10-6. 177-10-6 belongs to dioxole, auxiliary class Dioxolane,Spiro, name is 1,4-Dioxaspiro[4.5]decane, and the molecular formula is C3H3Br2ClO, Synthetic Route of 177-10-6.

Referemce:
https://en.wikipedia.org/wiki/1,3-Benzodioxole,
Dioxole | C3H4O2 – PubChem

Barbosa, Sandro L. published the artcileKetalization of ketones to 1,3-dioxolanes and concurring self-aldolization catalyzed by an amorphous, hydrophilic SiO₂-SO₃H catalyst under microwave irradiation, HPLC of Formula: 177-10-6, the publication is Journal of the Brazilian Chemical Society (2018), 29(8), 1663-1671, database is CAplus.

The amorphous, mesoporous SiO₂-SO₃H catalyst with a surface area of 115 m² g^-1 and 1.32 mmol H⁺ per g was very efficient for the protonation of ketones on a 10% (m/m) basis, and the catalyst-bound intermediates could be trapped by polyalcs. to produce ketals in high yields or suffer aldol condensations within minutes under low-power microwave irradiation The same catalyst could easily reverse the ketalization reaction.

Journal of the Brazilian Chemical Society published new progress about 177-10-6. 177-10-6 belongs to dioxole, auxiliary class Dioxolane,Spiro, name is 1,4-Dioxaspiro[4.5]decane, and the molecular formula is C8H14O2, HPLC of Formula: 177-10-6.

Referemce:
https://en.wikipedia.org/wiki/1,3-Benzodioxole,
Dioxole | C3H4O2 – PubChem

Tahara, Satoshi published the artcileThe third naturally occurring attractant toward zoospores of phytopathogenic Aphanomyces cochlioides from the Spinacia oleracea host plant, Related Products of dioxole, the publication is Bioscience, Biotechnology, and Biochemistry (2001), 65(8), 1755-1760, database is CAplus and MEDLINE.

A bioassay-guided survey of spinach leaf constituents resulted in 5,4′-dihydroxy-3,3′-dimethoxy-6,7-methylenedioxyflavone (I) being identified as the third naturally-occurring attractant in the host plant toward the zoospores of its pathogen, Aphanomyces cochlioides. The isolate showed attracting activity around Chromosorb W AW particles (60-80 mesh) coated with a 10^-5 M solution in a zoospore suspension. However, this activity was 1/100-1/1000 less than that of cochliophilin A, an attractant in the roots of spinach. Bioassays with the present isolate and related compounds revealed that 5,3′,4′-trihydroxy-3-methoxy-6,7-methylenedioxyflavone did not possess attractant activity, but rather weak antagonistic activity toward the former two attractants from spinach.

Bioscience, Biotechnology, and Biochemistry published new progress about 110204-45-0. 110204-45-0 belongs to dioxole, auxiliary class Flavonoids, name is 9-Hydroxy-6-phenyl-8H-[1,3]dioxolo[4,5-g]chromen-8-one, and the molecular formula is C12H14IN, Related Products of dioxole.

Referemce:
https://en.wikipedia.org/wiki/1,3-Benzodioxole,
Dioxole | C3H4O2 – PubChem

Pihlaja, Kalevi published the artcileCarbon-13 nuclear magnetic resonance studies on saturated heterocycles. Part I. Substituent effects on the carbon-13 chemical shifts of methyl-substituted 1,3-dioxolanes, Formula: C6H12O2, the publication is Finnish Chemical Letters (1977), 141-3, database is CAplus.

The 13C chem. shifts for 1,3-dioxolane and eleven Me-substituted derivatives are reported. The magnitude of the substituent effects, compared with those for cyclopentane and 1,3-dioxane, indicate that the 1,3-dioxolane ring is a dynamic mixture of conformations and that only 2,2-di-Me substitution shows increased steric demands.

Finnish Chemical Letters published new progress about 1193-11-9. 1193-11-9 belongs to dioxole, auxiliary class Dioxolanes, name is 2,2,4-Trimethyl-1,3-dioxolane, and the molecular formula is C6H12O2, Formula: C6H12O2.

Referemce:
https://en.wikipedia.org/wiki/1,3-Benzodioxole,
Dioxole | C3H4O2 – PubChem