scholarly journals Transformation of 3-(Furan-2-yl)-1,3-di(het)arylpropan-1-ones to Prop-2-en-1-ones via Oxidative Furan Dearomatization/2-Ene-1,4,7-triones Cyclization

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2637
Author(s):  
Roman O. Shcherbakov ◽  
Diana A. Eshmemet’eva ◽  
Anton A. Merkushev ◽  
Igor V. Trushkov ◽  
Maxim G. Uchuskin
Keyword(s):  
Double Bond ◽  
Furan Ring ◽  
Ring Formation ◽  
Oxidative Dearomatization

The approach to 3-(furan-2-yl)-1,3-di(het)arylprop-2-en-1-ones based on the oxidative dearomatization of 3-(furan-2-yl)-1,3-di(het)arylpropan-1-ones followed by an unusual cyclization of the formed di(het)aryl-substituted 2-ene-1,4,7-triones has been developed. The cyclization step is related to the Paal–Knorr synthesis, but the furan ring formation is accompanied in this case by a formal shift of the double bond through the formation of a fully conjugated 4,7-hydroxy-2,4,6-trien-1-one system or its surrogate.

Convenient Synthesis of Furopyranopyrandione Derivatives by the CAN-mediated Furan Ring Formation

Heterocycles ◽  
2003 ◽  
Vol 60 (4) ◽  
pp. 939 ◽  
Author(s):  
Kazuhiro Kobayashi ◽  
Katsunori Nagase ◽  
Osamu Morikawa ◽  
Hisatoshi Konishi
Keyword(s):  
Furan Ring ◽  
Ring Formation ◽  
Convenient Synthesis

Convenient Synthesis of Furopyranopyrandione Derivatives by the CAN-Mediated Furan Ring Formation.

ChemInform ◽  
2003 ◽  
Vol 34 (31) ◽  
Author(s):  
Kazuhiro Kobayashi ◽  
Katsunori Nagase ◽  
Osamu Morikawa ◽  
Hisatoshi Konishi
Keyword(s):  
Furan Ring ◽  
Ring Formation ◽  
Convenient Synthesis

Stoichiometric and Catalytic (η 5-Cyclopentadienyl)cobalt-Mediated Cycloisomerizations of Ene-Yne-Ene Type Allyl Propargyl Ethers

Synthesis ◽  
2019 ◽  
Vol 52 (03) ◽  
pp. 399-416
Author(s):  
Chu-An Chang ◽  
Stefan Gürtzgen ◽  
Erik P. Johnson ◽  
K. Peter C. Vollhardt
Keyword(s):  
Double Bond ◽  
Oxidative Coupling ◽  
Triple Bond ◽  
Furan Ring ◽  
Reductive Elimination ◽  
Potential Utility ◽  
Deuterium Labeling ◽  
Terminal Double Bond ◽  
Hydride Elimination ◽  
Diene Complex

The complexes CpCoL2 (Cp = C5H5; L = CO or CH2=CH2) mediate the cycloisomerizations of α,δ,ω-enynenes containing allylic ether linkages to 3-(oxacyclopentyl or cycloalkyl)furans via the intermediacy of isolable CpCo-η 4-dienes. A suggested mechanism comprises initial complexation of the triple bond and one of the double bonds, then oxidative coupling to a cobalt-2-cyclopentene, terminal double bond insertion to assemble a cobalta-4-cycloheptene, β-hydride elimination, and reductive elimination to furnish a CpCo-η 4-diene. When possible, the cascade continues through cobalt-mediated hydride shifts and dissociation of the aromatic furan ring. The outcome of a deuterium labeling experiment supports this hypothesis. The reaction exhibits variable stereoselectivity with a preference for the trans-product (or, when arrested, its syn-Me CpCo-η 4-diene precursor), but is completely regioselective in cases in which the two alkyne substituents are differentiated electronically by the presence or absence of an embedded oxygen. Regioselectivity is also attained by steric discrimination or blocking one of the two possible β-hydride elimination pathways. When furan formation is obviated by such regiocontrol, the sequence terminates in a stable CpCo-η 4-diene complex. The conversion of the cyclohexane-fused substrate methylidene-2-[5-(2-propenyloxy)-3-pentynyl]cyclohexane into mainly 1-[(1R*,3aS*,7aS*)-7a-methyloctahydroinden-1-yl]-1-ethanone demonstrates the potential utility of the method in complex synthesis.

scholarly journals Assessment of reactivities with explicit and implicit solvent models: QM/MM and gas-phase evaluation of three different Ag-catalysed furan ring formation routes

2019 ◽  
Vol 43 (39) ◽  
pp. 15706-15713 ◽  
Author(s):  
Péter Pál Fehér ◽  
András Stirling
Keyword(s):  
Gas Phase ◽  
Furan Ring ◽  
Ring Formation ◽  
Implicit Solvent ◽  
Continuum Solvation ◽  
Solvation Model ◽  
Solvent Models ◽  
Solute Interactions ◽  
Implicit Solvent Models ◽  
Phase Evaluation

A representative reaction illustrates cases where strong solvent–solute interactions can be sufficiently well captured by continuum solvation model rendering QM/MM unnecessary.

One-step furan ring formation: Synthesis of furo[3,2-h]quinolones

1997 ◽  
Vol 34 (6) ◽  
pp. 1731-1735 ◽  
Author(s):  
Masahiro Fujita ◽  
Hiroshi Egawa ◽  
Katsumi Chiba ◽  
Jun-Ichi Matsumoto
Keyword(s):  
Furan Ring ◽  
Ring Formation ◽  
One Step

scholarly journals (1R,2R)-8-Bromo-1-[(E)-2-(4-bromophenyl)ethenyl]-2-nitro-1,2-dihydronaphtho[2,1-b]furan

IUCrData ◽  
2016 ◽  
Vol 1 (4) ◽  
Author(s):  
Xiaoqin Fang ◽  
Yifeng Wang
Keyword(s):  
Double Bond ◽  
Medicinal Plants ◽  
Phenyl Ring ◽  
Furan Ring ◽  
Ring System ◽  
Dihedral Angles ◽  
Active Components ◽  
Compound C ◽  
Naphthyl Ring ◽  
The Mean

The title compound,C20H13Br2NO3, contains the dihydrobenzofuran moiety, which is present in the physiologically active components of many medicinal plants. The naphthyl ring system is nearly perpendicular to the phenyl ring, while the mean plane of the double bond is almost coplanar with the phenyl ring [dihedral angles of 79.14 (3) and 13.56 (1)°, respectively]. The nitro group and bromobenzene alkenyl group aretransto one another on opposite sides of the furan ring. There are two stereogenic centres, and each has theRconfiguration. In the crystal, there are very weak intermolecular C—H...Br interactions.

The Trajectory of the (η5-Cyclopentadienyl)cobalt-Mediated Cycloisomerization of Ene-Yne-Ene Type Allyl Propargylic Ethers to Furans: A DFT Appraisal

Synthesis ◽  
2021 ◽  
Author(s):  
Jonathan J Wong ◽  
Xiangyang Chen ◽  
Kendall N. Houk ◽  
Peter Vollhardt
Keyword(s):  
Double Bond ◽  
Oxidative Coupling ◽  
Triple Bond ◽  
Furan Ring ◽  
Reductive Elimination ◽  
Dft Methods ◽  
Structural Details ◽  
Hydride Elimination ◽  
Cis And Trans

The mechanisms by which the complexes CpCoL2 (Cp = C5H5; L = CO or CH2=CH2) mediate the cycloisomerizations of α,,-enynenes containing allylic ether linkages is probed by DFT methods. The outcomes corroborate experimental results and provide energetic and structural details of the trajectories leading to 3-(oxacyclopentyl or cycloalkyl)furans via the intermediacy of isolable CpCo-η4-dienes. They comprise initial stereoselective complexation of one of the double bonds and the triple bond, rate determining oxidative coupling to a triplet 16e cobalta-2-cyclopentene, and terminal double bond docking, followed by stereocontrolled insertion to assemble intermediate cis- and trans-fused triplet cobalta-4-cycloheptenes. A common indicator of the energetic facility of the latter is the extent of parallel alignment of alkene moiety and its target Co-Cα bond. The cobalta-4-cycloheptenes transform further by β-hydride elimination-reductive elimination to furnish CpCo-η4-dienes, sufficiently kinetically protected to allow for their experimental observation. The cascade continues through cobalt-mediated hydride shifts and dissociation of the aromatic furan ring. The findings in silico with respect to the stereo-, regio-, and chemoselectivity are in consonance with those obtained in vitro.

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