626-96-0Relevant articles and documents
Selectivity in the cycloadditions of carbonyl ylides with glyoxylates: An approach to the zaragozic acids-squalestatins
Hodgson, David M.,Bailey, James M.,Villalonga-Barber, Carolina,Drew, Michael G. B.,Harrison, Timothy
, p. 3432 - 3443 (2000)
Reaction of diazodiketoester 8 with glyoxylates in the presence of catalytic rhodium(n) acetate generates 6,8-dioxabicyclo[3.2.1]octanes 9 and 11 in good yield. Elaboration of 9 provides a suitable alcohol 25 for acid-catalysed rearrangement to give the 2,8-dioxabicyclo[3.2.1]octane skeleton 26 of the zaragozic acids-squalestatins. More substituted diazodiketoesters 36 and 40 also undergo highly regio- and diastereoselective cycloaddition with glyoxylates to give the cycloadducts 41,43 and 44. The Royal Society of Chemistry 2000.
Gas-phase reactions of nopinone, 3-Isopropenyl-6-oxo-heptanal, and 5-Methyl-5-vinyltetrahydrofuran-2-ol with OH, NO3, and Ozone
Calogirou, Aggelos,Jensen, Niels R.,Nielsen, Claus J.,Kotzias, Dimitrios,Hjorth, Jens
, p. 453 - 460 (1999)
In the troposphere, α-pinene, β-pinene, limonene, and linalool are mainly oxidized to pinonaldehyde, nopinone, 3-isopropenyl-6-oxoheptanal (IPOH), and 5-methyl-5-vinyltetrahydrofuran-2-ol (MVT), respectively. The rate constant of the reactions of nopinone, IPOH, and MVT with OH, NO3, and O3 were determined by long path FT-IR spectroscopy, and the oxidation products from the reactions between the OH radical and pinonaldehyde, nopinone, IPOH, and MVT were investigated using GC-MS and HPLC. The reaction rate constants (k) for the reactions have been determined at 740 ± 5 Torr and 298 ± 5 K, and a number of reaction products were identified. The rate constants obtained for the reactions with nopinone were kOH = (1.7 ± 0.2) x 10-11, kNO3 -15, and kO3, -21; for the reactions with IPOH were kOH = (1.1 ± 0.3) x 10-10, kNO3 = (2.6 ± 0.8) x 10-13, and kO3, = (8.3 ± 2.2) x 10-18; and for the reactions with MVT were kOH = (7.4 ± 0.9) x 10-11, kNO3 = (2.0 ± 0.9) x 10-14, and kO3, = (3.8 ± 0.8) x 10-18 (all units are in cm3 molecule-1 s-1, and uncertainties are given as two σ on the experimental data). From the results obtained in this investigation and previous studies, it was concluded that a typical atmospheric lifetime with respect to chemical reactions was only a few hours for pinonaldehyde, IPOH, and MVT but was much longer·for nopinone with a lifetime of about 10 h.
Solvent effect on the rate and direction of furfural transformations during hydrogenation over the Pd/C catalyst
Belskaya, O. B.,Likholobov, V. A.,Mironenko, R. M.
, p. 64 - 69 (2022/02/25)
The rate and directions of transformations during the liquid-phase hydrogenation of furfural with molecular hydrogen in the presence of the 5%Pd/C catalyst (at 423 K, 3 MPa) depend substantially on the chemical nature of the solvent. The main products of
Atroposelective Synthesis of Axially Chiral N-Arylpyrroles by Chiral-at-Rhodium Catalysis
Chen, Shuming,Han, Feng,Houk, K. N.,Ivlev, Sergei,Meggers, Eric,Xie, Xiulan,Ye, Chen-Xi
supporting information, p. 13552 - 13556 (2020/06/05)
A transformation of fluxional into configurationally stable axially chiral N-arylpyrroles was achieved with a highly atroposelective electrophilic aromatic substitution catalyzed by a chiral-at-metal rhodium Lewis acid. Specifically, N-arylpyrroles were alkylated with N-acryloyl-1H-pyrazole electrophiles in up to 93 percent yield and with up to >99.5 percent ee, and follow-up conversions reveal the synthetic utility of this new method. DFT calculations elucidate the origins of the observed excellent atroposelectivity.
Domino Carbopalladation/C-H Activation as a Quick Access to Polycyclic Frameworks
Saha, Nemai,Wang, Haiwen,Zhang, Shengyi,Du, Yongliang,Zhu, Daqian,Hu, Yumin,Huang, Peng,Wen, Shijun
supporting information, p. 712 - 715 (2018/02/09)
A new type of domino reaction for synthesis of heterocycles fusing the important bioactive cores, such as oxindole, indoline, and isoquinoline, is presented. Upon exposure to the very common palladium catalyst, the conceptually designed N-alkenyl iodobiaryls undergo a sequential carbopalladation/C-H activation to build polycyclic frameworks. These novel unique frameworks may provide structure sources in fragment-based drug discovery.