Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Asymmetric Aldol Reaction of 3-Acetyl-2H-chromen-2-ones and Isatins Catalyzed by a Bifunctional Quinidine Urea Catalyst.

ABSTRACT: The asymmetric aldol reaction of 3-acetyl-2H-chromen-2-ones and isatins has been realized by using a bifunctional quinidine-derived urea as the catalyst. The corresponding 3-hydroxyoxindole derivatives containing a 2H-chromen-2-one moiety were obtained in good yields and high enantioselectivities. When (Z)-ethyl 2-benzylideneacetoacetate was used as the substrate, a mixture of two diastereomers (both Z and E) was obtained due to the isomerization of the double bond under the reaction conditions.

SUBMITTER: Abbaraju S

PROVIDER: S-EPMC4019438 | biostudies-literature | 2014 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Asymmetric Aldol Reaction of 3-Acetyl-2H-chromen-2-ones and Isatins Catalyzed by a Bifunctional Quinidine Urea Catalyst.

Abbaraju Santhi S Zhao John Cong-Gui JC

Advanced synthesis & catalysis 20140101 1

The asymmetric aldol reaction of 3-acetyl-2H-chromen-2-ones and isatins has been realized by using a bifunctional quinidine-derived urea as the catalyst. The corresponding 3-hydroxyoxindole derivatives containing a 2H-chromen-2-one moiety were obtained in good yields and high enantioselectivities. When (Z)-ethyl 2-benzylideneacetoacetate was used as the substrate, a mixture of two diastereomers (both Z and E) was obtained due to the isomerization of the double ...[more]

PMID: 24839435

Similar Datasets

8-Acetyl-4-methyl-2-oxo-2H-chromen-7-yl acetate.

Project description:In the title compound, C(14)H(12)O(5), the benzopyran-2-one ring system is approximately planar [maximum deviation = 0.018?(1)?Å]; the mean plane is oriented at dihedral angles of 52.26?(11) and 72.92?(7)°, respectively, to the acetyl and acet-oxy groups. In the crystal, ?-? stacking is observed between parallel benzene rings of adjacent mol-ecules, the centroid-centroid distance being 3.6774?(17)?Å. Inter-molecular weak C-H?O hydrogen bonding, and C=O?C=O [O?C = 3.058?(3)?Å] and C=O?? [O?centroid = 3.328?(2)?Å] inter-actions occur in the crystal structure.

| S-EPMC3239025 | biostudies-literature

3-Acetyl-4-hy-droxy-6,7-dimethyl-2H-chromen-2-one.

Project description:In the title coumarin derivative, C(13)H(12)O(4), the 2H-chromene ring system is essentially planar [maximum deviation = 0.047?(1)?Å]. An intra-molecular hydrogen bond is observed between the hy-droxy and the ketonic O atoms. In the crystal, pairs of inter-molecular C-H?O hydrogen bonds link inversion-related mol-ecules into dimers. Additional inter-molecular C-H?O hydrogen bonds further inter-connect these dimers into two-dimensional arrays incorporating R(2) (2)(9) ring motifs.

| S-EPMC3011552 | biostudies-literature

Chasing ChEs-MAO B Multi-Targeting 4-Aminomethyl-7-Benzyloxy-2H-Chromen-2-ones.

Project description:A series of 4-aminomethyl-7-benzyloxy-2H-chromen-2-ones was investigated with the aim of identifying multiple inhibitors of cholinesterases (acetyl- and butyryl-, AChE and BChE) and monoamine oxidase B (MAO B) as potential anti-Alzheimer molecules. Starting from a previously reported potent MAO B inhibitor (3), we studied single-point modifications at the benzyloxy or at the basic moiety. The in vitro screening highlighted triple-acting compounds (6, 8, 9, 16, 20) showing nanomolar and selective MAO B inhibition along with IC50 against ChEs at the low micromolar level. Enzyme kinetics analysis toward AChE and docking simulations on the target enzymes were run in order to get insight into the mechanism of action and plausible binding modes.

| S-EPMC6943664 | biostudies-literature

Crystal structure of a new polymorph of 3-acetyl-8-meth-oxy-2H-chromen-2-one.

Project description:A new polymorphic form of the title compound, C12H10O4, is described in the ortho-rhom-bic space group Pbca and Z = 8, as compared to polymorph I, which crystallizes in the monoclinic space group C2/c and Z = 8 [Li et al. (2012). Chin. J. Struct. Chem. 31, 1003-1007.]. In polymorph II, the coumarin ring system is almost planar (r.m.s. deviation = 0.00129?Å). In the crystal, mol-ecules are connected by Csp 3-H?O and Car-H?O hydrogen bonds, forming mol-ecular sheets linked into zigzag shaped layers along the b-axis direction. The three-dimensional lattice is assembled through stacking of the zigzag layers by ?-? inter-actions with a centroid-to-centroid distance of 3.600?(9)?Å and anti-parallel C=O?C=O inter-actions with a distance of 3.1986?(17)?Å, which give rise to a helical supra-molecular architecture.

| S-EPMC6895931 | biostudies-literature

2H-Chromen-4(3H)-one.

Project description:In the title compound, C(9)H(8)O(2), a benzo-annulated heterocyclic ketone, the non-aromatic six-membered ring adopts an E(2) conformation. In the crystal, C-H?O contacts connect the mol-ecules into double sheets perpendicular to the crystallographic a axis. The centroid-centroid distance for two ?-systems is 3.7699?(6)?Å.

| S-EPMC3089272 | biostudies-literature

Asymmetric synthesis of 1H-pyrrol-3(2H)-ones from 2,3-diketoesters by combination of aldol condensation with benzilic acid rearrangement.

Project description:An efficient two-step protocol for the asymmetric synthesis of 1H-pyrrol-3(2H)-one derivatives in 99% ee from conveniently accessed 2,3-diketoesters has been developed.

| S-EPMC4679521 | biostudies-literature

Urea-Derivative Catalyzed Enantioselective Hydroxyalkylation of Hydroxyindoles with Isatins.

Project description:The enantioselective transformations of indoles preferentially take place in the more-reactive azole ring. However, the methods for the enantioselective functionalization of the indole benzene ring are scarce. In this paper, a series of bifunctional (thio)urea derivatives were used to organocatalyze the enantioselective Friedel-Crafts hydroxyalkylation of indoles with isatins. The resulting products were obtained in good yields (65-90%) with up to 94% enantiomer excess (ee). The catalyst type and the substrate scope were broadened in this methodology.

| S-EPMC6864875 | biostudies-literature

3-Benzyl-2H-chromen-2-one.

Project description:The title compound, C(16)H(12)O(2), is a coumarin which was isolated from stones of the Chinese traditional medicine Clausena lansium. The pyrone ring is almost planar, with a mean deviation of 0.0135?(4)?Å. The benzene ring (A) of the benzopyrone unit forms dihedral angles of 1.82?(5) and 72.86?(2)° with the pyrone ring and the substituent benzene ring, respectively. The crystal structure is stabilized by weak ?-? stacking inter-actions, with a minimum centroid-centroid distance between benzene rings of 3.6761?(7)?Å.

| S-EPMC3344613 | biostudies-literature

4,7,8-Trimethyl-2H-chromen-2-one.

Project description:The mol-ecule of the title compound, C(12)H(12)O(2), is essentially planar, with a maximum deviation from the mean plane of all non-H atoms of 0.038 (1) Å for the methyl C atom in the 8-position. The crystal structure is characterized by anti-parallel π-π stacking along the c axis, with centroid-centroid distances as short as 3.866 (1) Å. In the crystal, C-H⋯O hydrogen bonds connect the mol-ecules across the stacks into ribbons in the a-axis direction.

| S-EPMC3343979 | biostudies-literature

Ni–Fe phosphide deposited carbon felt as free-standing bifunctional catalyst electrode for urea electrolysis

Project description:A free-standing catalyst electrode for the urea oxidation reaction (UOR) and hydrogen evolution reaction (HER) in a urea electrolysis cell was synthesized by electroplating a Ni–Fe alloy onto carbon felt, followed by phosphidation (P-NiFe@CF). The prepared P-NiFe@CF catalyst consisted of Ni5P4, NiP2, and FeP with 3D flower-like P-NiFe architecture on CF. P-NiFe@CF exhibited excellent electrocatalytic activity for the UOR (demanding only 1.39 V (vs. RHE) to achieve 200 mA cm−2), and for the HER with a low overpotential of 0.023 V (vs. RHE) at 10 mA cm−2, indicating its feasibility as a bifunctional catalyst electrode for urea electrolysis. A urea electrolysis cell with P-NiFe@CF as both the free-standing anode and cathode generated a current density of 10 mA cm−2 at a cell potential of 1.37 V (vs. RHE), which is considerably lower than that of water electrolysis, and also lower than previously reported values. The results indicate that the P-NiFe@CF catalyst electrodes can be used as free-standing bifunctional electrodes for urea electrolyzers.

| S-EPMC8578333 | biostudies-literature