scholarly journals One-pot cross-enyne metathesis (CEYM)–Diels–Alder reaction of gem-difluoropropargylic alkynes

2013 ◽  
Vol 9 ◽  
pp. 2688-2695 ◽  
Author(s):  
Santos Fustero ◽  
Paula Bello ◽  
Javier Miró ◽  
María Sánchez-Roselló ◽  
Günter Haufe ◽  
...  

Propargylic difluorides 1 were used as starting substrates in a combination of cross-enyne metathesis and Diels–Alder reactions. Thus, the reaction of 1 with ethylene in the presence of 2nd generation Hoveyda–Grubbs catalyst generates a diene moiety which in situ reacts with a wide variety of dienophiles giving rise to a small family of new fluorinated carbo- and heterocyclic derivatives in moderate to good yields. This is a complementary protocol to the one previously described by our research group, which involved the use of 1,7-octadiene as an internal source of ethylene.

2009 ◽  
Vol 2009 (8) ◽  
pp. 499-504 ◽  
Author(s):  
Jianjun Li ◽  
Jia Li ◽  
Weike Su

Proline triflate was found to catalyse efficiently the one-pot synthesis of 2H-pyranotetrahydroquinolines from aryl imines, and 3,4-dihydro-2 H-pyran with high stereoselectivity. The aryl imines were formed in situ from aromatic amines and arylaldehydes.


Synlett ◽  
2001 ◽  
Vol 2001 (11) ◽  
pp. 1784-1786 ◽  
Author(s):  
Marcial Moreno-Mañas ◽  
Roser Pleixats ◽  
Antoni Santamaria

1997 ◽  
Vol 75 (9) ◽  
pp. 1163-1171 ◽  
Author(s):  
Brian A. Keay ◽  
Shawn P. Maddaford ◽  
Walter A. Cristofoli ◽  
Neil G. Andersen ◽  
Marco S. Passafaro ◽  
...  

This paper describes the chemistry presented during the Merck Frosst Centre for Therapeutic Research Lecture Award given at the 79th Chemistry in Canada Conference held in St. John's, Newfoundland in June 1996. The first section describes the synthesis of (+)-xestoquinone using an asymmetric palladium-catalyzed polyene cyclization as the key step that creates the C and D rings and the stereogenic centre (68% ee) in one step. Extensions of the work involving an in situ Suzuki reaction are presented. The synthesis of C2-symmetric biaryls and the synthesis of a recently isolated binaphthyl natural product is described using this new method. A new one-pot desilylation–oxidation procedure of silyl ethers is described in detail for the preparation of aldehydes and ketones directly without the need for the isolation of the alcohol intermediate. Finally, a highly diastereoselective (>97%) Diels–Alder reaction is presented using (+)-cis,cis-spiro[4.4]nonane-1,6-diol as a new chiral auxiliary. One of the alcohols is attached to a pivalate, the other to an acrylate, and the Diels–Alder reaction with cyclopentadiene provides only one adduct (by 1H NMR and HPLC) with the endo stereochemistry. Keywords: (+)-xestoquinone, asymmetric palladium-catalyzed polyene cyclization, in situ Suzuki reaction, desilylation–oxidation reaction, spirodiols, chiral auxiliaries.


2013 ◽  
Vol 28 (4) ◽  
pp. 307-311 ◽  
Author(s):  
M.A. Macías ◽  
J.A. Henao ◽  
Arnold R. Romero Bohórquez ◽  
Vladimir V. Kouznetsov

The 2,4-diaryl 1,2,3,4-tetrahydroquinoline derivative (1), described in the title (Chemical formula: C23H22N2O3), was synthesized via the “one-pot” three-component imino Diels–Alder reaction catalyzed by Cu(OTf)2. Molecular characterization was performed by 1H and 13C NMR, Fourier transform-infrared, and gas chromatography-mass spectrometry. The X-ray powder diffraction pattern for the title compound was analyzed and found to be crystallized in an orthorhombic system with space group P212121 (No. 19) and refined unit-cell parameters a = 8.6415(8) Å, b = 12.679(2) Å, c = 17.601(2) Å, and V = 1928.4(2) Å3.


Tetrahedron ◽  
2008 ◽  
Vol 64 (3) ◽  
pp. 559-567 ◽  
Author(s):  
Raja Ben-Othman ◽  
Mohamed Othman ◽  
Servane Coste ◽  
Bernard Decroix

2020 ◽  
Vol 16 ◽  
pp. 880-887
Author(s):  
Benjamin Laroche ◽  
Thomas Bouvarel ◽  
Martin Louis-Sylvestre ◽  
Bastien Nay

A diversity-oriented synthesis (DOS) approach has been used to functionalize 17-ethynyl-17-hydroxysteroids through a one-pot procedure involving a ring-closing enyne metathesis (RCEYM) and a Diels–Alder reaction on the resulting diene, under microwave irradiations. Taking advantage of the propargyl alcohol moiety present on commercially available steroids, this classical strategy was applied to mestranol and lynestrenol, giving a collection of new complex 17-spirosteroids.


2021 ◽  
Vol 17 ◽  
pp. 2425-2432
Author(s):  
Ren-Jie Fang ◽  
Chen Yan ◽  
Jing Sun ◽  
Ying Han ◽  
Chao-Guo Yan

The p-TsOH-catalyzed Diels–Alder reaction of 3-(indol-3-yl)maleimides with chalcone in toluene at 60 °C afforded two diastereoisomers of tetrahydropyrrolo[3,4-c]carbazoles, which can be dehydrogenated by DDQ oxidation in acetonitrile at room temperature to give the aromatized pyrrolo[3,4-c]carbazoles in high yields. On the other hand, the one-pot reaction of 3-(indol-3-yl)-1,3-diphenylpropan-1-ones with chalcones or benzylideneacetone in acetonitrile in the presence of p-TsOH and DDQ resulted in polyfunctionalized carbazoles in satisfactory yields. The reaction mechanism included the DDQ oxidative dehydrogenation of 3-(indol-3-yl)-1,3-diphenylpropan-1-ones to the corresponding 3-vinylindoles, their acid-catalyzed Diels–Alder reaction and sequential aromatization process.


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