Imino Diels-Alder Reaction Research Articles

ChemInform Abstract: Imino Diels—Alder Reactions: One‐Pot Synthesis of Tetrahydroquinolines.

AbstractThe three‐component coupling proceeds within short reaction times.

Synthesis and SAR studies of chiral non-racemic dexoxadrol analogues as uncompetitive NMDA receptor antagonists

A series of chiral non-racemic dexoxadrol analogues with various substituents in position 4 of the piperidine ring was synthesized and pharmacologically evaluated. Only the enantiomers having ( S)-configuration at the 2-position of the piperidine ring and 4-position of the dioxolane ring were considered. Key steps in the synthesis were an imino-Diels–Alder reaction of enantiomerically pure imine ( S)- 13, which had been obtained from d-mannitol, with Danishefsky’s Diene 14 and the replacement of the p-methoxybenzyl protective group with a Cbz-group. It was shown that ( S, S)-configuration of the ring junction (position 2 of the piperidine ring and position 4 of the dioxolane ring) and axial orientation of the C-4-substituent ((4 S)-configuration) are crucial for high NMDA receptor affinity. 2-(2,2-Diphenyl-1,3-dioxolan-4-yl)piperidines with a hydroxy moiety (( S, S, S)- 5, K i = 28 nM), a fluorine atom (( S, S, S)- 6, WMS-2539, K i = 7 nM) and two fluorine atoms (( S, S)- 7, K i = 48 nM) in position 4 represent the most potent NMDA antagonists with high selectivity against σ 1 and σ 2 receptors and the polyamine binding site of the NMDA receptor. The NMDA receptor affinities of the new ligands were correlated with their electrostatic potentials, calculated gas phase proton affinities (negative enthalpies of deprotonation) and dipole moments. According to these calculations decreasing proton affinity and increasing dipole moment are correlated with decreasing NMDA receptor affinity.

Yb(OTf) 3: an efficient catalyst for the synthesis of 3-arylbenzo [ f]quinoline-1,2-dicarboxylate derivatives via imino-Diels–Alder reaction

A mild and facile method for the synthesis of 3-arylbenzo[ f]quinoline-1,2-dicarboxylate derivatives is reported by an imino-Diels–Alder reaction in high yields (76–92%). This procedure includes a novel three-component reaction of aromatic aldehyde, naphthalen-2-amine, and but-2-ynedioate catalyzed by Yb(OTf) 3 in toluene. The results are obviously different from those of the simple substituted aniline-involved reactions catalyzed by ZnCl 2 or KOH in the literature.

ChemInform Abstract: Synthesis of 2-Phenyldecahydroquinolin-4-ones via Imino Diels-Alder Reaction: Influence of the Imine Nitrogen Substituent on the Reaction Course and on the Heterocycle Conformation.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: High Degree of Exo Selectivity in Imino Diels-Alder Reactions Catalyzed by tert-Butyldimethylsilyl Triflate.

ChemInform Abstract: High Degree of Exo Selectivity in Imino Diels-Alder Reactions Catalyzed by tert-Butyldimethylsilyl Triflate.

Perhydrofuro[3,2-c]-, perhydropyrano[3,2-c]-, and 4-ethoxy-2-(5-R-furan-2-yl)tetrahydroquinolines. Synthesis and transformations

Partly hydrogenated 2-[5-methyl(bromo, nitro)furan-2-yl]-substituted furo[3,2-c]quinolines, pyrano-[3,2-c]quinolines, and 4-ethoxyquinolines were synthesized by the imino Diels-Alder (Povarov) reaction. Cycloadditions of these compounds with maleic, citraconic, and dibromomaleic anhydrides, as well as with acryloyl, methacryloyl, and cinnamoyl chlorides led to the formation of substituted epoxyisoindolo[2,1-a]-quinolines and -quinolinecarboxylic acids. Oxidation of the double C=C bond in the adducts, esterification of the carboxy group, and aromatization of the 7-oxabicycloheptene fragment were accomplished.

Mild and Simple Access to Diverse 4-Amino-substituted 2-Phenyl-1,2,3,4-tetrahydroquinolines and 2-Phenylquinolines Based on a Multicomponent Imino Diels–Alder Reaction

A straightforward synthesis of new 1-(2-phenyl-1,2,3,4-tetrahydroquinolin-4-yl) pyrrolidin-2-ones/azepan-2-one from N-vinyl caprolactam/N-vinylpyrrolidin-2-one and N-benzylideneaniline via the imino Diels–Alder reaction has been reported for the first time. Antimony(III) chloride has been shown to effectively catalyze imino-Diels–Alder reaction to afford both 2-phenylquinoline and 2-phenyl-1,2,3,4-tetrahydroquinolin derivatives in excellent yields at ambient temperature. The cis diastereoselectivity to give cis 2-phenyl-1,2,3,4-tetrahydroquinolines is also highlighted in this reaction.

ChemInform Abstract: An Efficient and Short Synthesis of 4‐Aryl‐3‐methyltetrahydroquinolines from N‐Benzylanilines and Propenylbenzenes Through Cationic Imino Diels—Alder Reactions.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Imino Diels–Alder reaction — An efficient synthetic protocol for 2-methyl-4-substituted tetrahydroquinolines catalyzed by copper dipyridine dichloride

For the first time, copper dipyridine dichloride (CuPy2Cl2) is used as an efficient and reusable catalyst for the imino Diels–Alder reaction of para-substituted anilines with N-vinylpyrrolidinone, N-vinylcarbazole, and N-vinylcaprolactam in acetonitrile to afford the corresponding 2-methyl-4-substituted-1,2,3,4-tetrahydroquinoline derivatives in excellent yields with good purity. The products were characterized by FTIR,1H NMR,13C NMR, MS, and elemental analysis.

ChemInform Abstract: Chemo‐ and Regioselective Imino Diels—Alder Reactions: Synthesis of Functionalized Novel Quinolin‐3‐one and Quinoline Derivatives.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Synthesis of new cis-fused tetrahydrochromeno[4,3-b]quinolines and their antiproliferative activity studies against MDA-MB-231 and MCF-7 breast cancer cell lines

New cis-fused tetrahydrochromeno[4,3-b]quinolines have been synthesized by intramolecular [4+2] imino-Diels–Alder reactions of 2-azadienes derived in situ from aromatic amines and 7-O-prenyl derivatives of 8-formyl-2,3-disubstituted chromenones in the presence of 20mol% Yb(OTf)3 in acetonitrile under reflux conditions in good to excellent yields. The structures were established by spectroscopic data and further confirmed by X-ray diffraction analysis. These compounds were evaluated for their antiproliferative activity against MDA-MB-231 and MCF-7 breast cancer cells. The results showed that compounds 3e, 3f, and 3k exhibit significant antiproliferative activity against MCF-7 breast cancer cells and low inhibitory activity against MDA-MB-231 breast cancer cell lines. Compound 3h displayed activity as comparable to tamoxifen on both the cell lines.

An Efficient and Short Synthesis of 4-Aryl-3-methyltetrahydroquinolines from N-Benzylanilines and Propenylbenzenes through Cationic Imino Diels-Alder Reactions

A new, simple protocol for the BF 3 ·OEt 2 -catalyzed synthesis of diverse 3-methyl-4-aryl-1,2,3,4-tetrahydroquinolines using easily available starting materials and renewable phenylpropenoid reagents is described. These compounds could serve as interesting models in pharmacological studies.

2-Ethyl-6-(2-pyridyl)-5,6,6a,11b-tetrahydro-7H-indeno[2,1-c]quinoline

The title compound, C23H22N2, was obtained using the three-component imino Diels–Alder reaction via a one-pot condensation between anilines, α-pyridine­carboxy­aldehyde and indene using BF3·OEt2 as the catalyst. The mol­ecular structure reveals the cis-form as the unique diastereoisomer. The crystal structure comprises one-dimensional zigzag ribbons connected via N—H⋯N hydrogen bonds. C—H⋯π inter­actions also occur.

Imino Diels–Alder reactions: One-pot synthesis of tetrahydroquinolines

An efficient synthesis of tetrahydroquinoline derivatives is reported via three component coupling reactions of aldehydes and anilines with various dienophiles in the presence of a catalytic amount of perchloric acid adsorbed on silica gel (HClO 4–SiO 2) under mild reaction conditions.

Chemo- and Regioselective Imino Diels-Alder Reactions: Synthesis of Functionalized Novel Quinolin-3-one and Quinoline Derivatives

Regio- and catalyst selective imino Diels-Alder reactions of vinyl/isopropenyl pyrimidinones with N-arylimines in the presence of metal salts viz. magnesium(II) bromide, zinc(II) chloride, indium(III) chloride, yttrium triflate and scandium triflate, are described. An unprecedented oxidation of methylene to carbonyl has been shown to accompany the imino Diels-Alder reactions of isopropenyl pyrimidinones in the presence of yttrium and scandium triflates. Chemoselective effect of different Lewis acids used as catalysts in these reactions has been rationalized.

Iodine-promoted imino-Diels–Alder reaction of fluorinated imine with enol ether: synthesis of 2-perfluorophenyl tetrahydroquinoline derivatives

Iodine was used to catalyze the hetero-Diels–Alder reaction of pentafluorobenzylidineaniline (C 6F 5CH NAr 1) with enol ethers to afford the corresponding tetrahydroquinolines derivatives as a mixture of cis/ trans stereoisomers in moderate yields. These products could also be prepared by one-pot, three-component reaction of pentafluorophenylaldehyde, anilines, and enol ethers under the same reaction condition. Mild and neutral reaction conditions, facile experimental procedure, and low price of iodine should make this method attractive for practical synthesis of many fluorinated tetrahydroquinoline derivatives.

Tungstophosphoric Acid–Catalyzed Imino-Diels–Alder Reaction: An Efficient One-Pot Synthesis of Pyrano- and Furanoquinoline Derivatives

Tungstophosphoric acid has been found to be an efficient catalyst for the synthesis of pyranos- and furanoquinolines through the Imino-Diels–Alder reaction involving one-pot coupling of benzaldehydes, anilines, and 3,4-dihydro-2 H-pyran or 2,3-dihydrofuran. The products are formed at room temperature in excellent yields in a short period of time.

Intramolecular Imino Diels−Alder Reaction: Progress toward the Synthesis of Uncialamycin

We herein described an intramolecular imino Diels-Alder reaction promoted with BF(3).OEt(2)/DDQ affording substituted quinolines. Using this procedure, we prepared the chiral quinoline moiety of the uncialamycin, a new enediyne natural product.

Using Imino Diels-Alder Reaction to Access Isomeric Ellipticine Derivatives

Using Imino Diels-Alder Reaction to Access Isomeric Ellipticine Derivatives

ChemInform Abstract: A One‐Pot Synthetic Approach to the Functionalized Isomeric Ellipticine Derivatives Through an Imino Diels—Alder Reaction.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.