1530-39-8Relevant articles and documents
Chiral Imidodiphosphoric Acid-Catalyzed Highly Diastereo- and Enantioselective Synthesis of Poly-Substituted 3,4-Dihydro-2 H-pyrans: [4 + 2] Cycloadditions of β,γ-Unsaturated α-Ketoesters and 3-Vinylindoles
Guan, Xu-Kai,Liu, Guo-Feng,An, Dong,Zhang, Heng,Zhang, Suo-Qin
supporting information, p. 5438 - 5442 (2019/08/01)
Imidodiphosphoric acids were employed to catalyze inverse-electron-demand hetero-Diels-Alder reaction of β,γ-unsaturated α-ketoesters and 3-vinylindoles. A series of optically active 3,4-dihydro-2H-pyran derivatives with three contiguous stereogenic centers was synthesized in excellent yields (70-99%), diastereoselectivities (>20:1), and enantioselectivities (73-99%). The resulting indole containing 3,4-dihydro-2H-pyran could be converted to tetrahydropyran derivatives, which appear in several biological active compounds by simple hydrogenation reduction.
Novel (E)-5-styryl-2,2′-bithiophene derivatives as ligands for β-amyloid plaques
Cui, Mengchao,Li, Zijing,Tang, Ruikun,Jia, Hongmei,Liu, Boli
experimental part, p. 2908 - 2916 (2011/07/08)
In continuation of our investigation on the bithiophene structure as potential β-amyloid probes, a series of (E)-5-styryl-2,2′-bithiophene (SBTP) derivatives was designed and synthesized. In vitro binding showed that all of them displayed high binding affinities to Aβ1-42 aggregates (Ki = 0.10-41.05 nM). Moreover, two radio-iodinated probes, [125I]-(E)-5-(4-iodostyryl)-2,2′-bithiophene ([ 125I]8) and [125I]-(E)-5-iodo-5′-(4-methoxystyryl)- 2,2′-bithiophene ([125I]31) were prepared. Both of them displayed specific labeling of Aβ plaques in the brain sections of AD model mice with low background. In vivo biodistribution in normal mice indicated that [125I]8 exhibited high initial brain uptake (2.11% ID/g at 2 min) and rapid clearance (0.41% ID/g at 30 min). These preliminary results suggest that SBTP derivatives may be served as novel β-amyloid imaging probes.
Synthesis of novel sulfonyl-stabilized phosphorus ylides, and the kinetics and mechanism of their conventional and flash vacuum pyrolysis reactions
Al-Bashir, Rasha F.,Al-Awadi, Nouria A.,El-Dusouqui, Osman M.E.
, p. 1543 - 1553 (2007/10/03)
Nine substituted sulfonyl-stabilized phosphorus ylides were prepared by treating their intermediate ylide analogues with phenylmethanesulfonyl fluoride. The stoichiometric ratio of the reactants for each preparation needed to be adjusted according to the basicity of each ylide intermediate. The nine ylide compounds were then subjected to conventional (sealed-tube) gas-phase pyrolysis at 470-545 K. The pyrolytic reactions were homogeneous and obeyed a first-order rate equation. The values of the Arrhenius log A (s-1) and E a (kJ mol-1) obtained for these reactions averaged 11.12 ± 2.00 and 131.8 ± 24.4, respectively. Analysis of the pyrolysates from conventional pyrolysis and from flash vacuum pyrolysis at 600 K showed the products to be complex mixtures of triphenylphosphine, triphenylphosphine oxide, triphenylphosphine sulfide, and symmetric and unsymmetric alkenes. Conventional pyrolysis also gave novel mixed sulfones and, for the p-methoxyaryl substituent, p-anisaldehyde. The products of the reactions under study are explained on the basis of a mechanism involving a sulfonyl carbene intermediate, and the reaction mechanism is used to rationalize the kinetic results and molecular reactivities.
