Stereoselective α-indolylation of enals via an organocatalytic formal cross-coupling with indoles

2015 ◽  
Vol 13 (33) ◽  
pp. 8869-8874 ◽  
Author(s):  
Yang Hu ◽  
Lei Ju ◽  
Lin Lu ◽  
Hongmei Ma ◽  
Xinhong Yu

A novel organocatalytic one-pot cascade bromination–Michael addition dearomatization–nucleophilic rearrangement aromatization cascade process for the direct α-indolylation of unfunctionalized enals from readily available indoles with good yields and high E selectivity has been developed with great simplicity and practicality.

2019 ◽  
Vol 15 ◽  
pp. 1416-1424
Author(s):  
Ruben Pomar Fuentespina ◽  
José Angel Garcia de la Cruz ◽  
Gabriel Durin ◽  
Victor Mamane ◽  
Jean-Marc Weibel ◽  
...  

1,3-Enynes are important building blocks in organic synthesis and also constitute the key motif in various bioactive natural products and functional materials. However, synthetic approaches to stereodefined substituted 1,3-enynes remain a challenge, as they are limited to Wittig and cross-coupling reactions. Herein, stereodefined 1,3-enynes, including tetrasubstituted ones, were straightforwardly synthesized from cis or trans-alkynylated oxiranes in good to excellent yields by a one-pot cascade process. The procedure relies on oxirane deprotonation, borylation and a stereospecific rearrangement of the so-formed alkynyloxiranyl borates. This stereospecific process overall transfers the cis or trans-stereochemistry of the starting alkynyloxiranes to the resulting 1,3-enynes.


2017 ◽  
Vol 15 (25) ◽  
pp. 5272-5274 ◽  
Author(s):  
Shenghu Yan ◽  
Shengyu Cao ◽  
Jiangtao Sun

A novel approach to synthesize seven-membered heterocycles is established by reacting amide tethered terminal alkynes with aryl diazoacetates in a one-pot reaction.


RSC Advances ◽  
2014 ◽  
Vol 4 (29) ◽  
pp. 15007-15010 ◽  
Author(s):  
Wei Yang ◽  
Yu Zhou ◽  
Haifeng Sun ◽  
Lei Zhang ◽  
Fei Zhao ◽  
...  

A metal-free cascade process for the synthesis of highly substituted pyrroles with high yields and broad substrate tolerance via enamine, aza-Michael addition and TBHP, activated carbon oxidative aromatization is reported.


2019 ◽  
Author(s):  
Victor Bloemendal ◽  
Floris P. J. T. Rutjes ◽  
Thomas J. Boltje ◽  
Daan Sondag ◽  
Hidde Elferink ◽  
...  

<p>In this manuscript we describe a modular pathway to synthesize biologically relevant (–)-<i>trans</i>-Δ<sup>8</sup>-THC derivatives, which can be used to modulate the pharmacologically important CB<sub>1</sub> and CB<sub>2</sub> receptors. This pathway involves a one-pot Friedel-Crafts alkylation/cyclization protocol, followed by Suzuki-Miyaura cross-coupling reactions and gives rise to a series of new Δ<sup>8</sup>-THC derivatives. In addition, we demonstrate using extensive NMR evidence that similar halide-substituted Friedel-Crafts alkylation/cyclization products in previous articles were wrongly assigned as the para-isomers, which also has consequence for the assignment of the subsequent cross-coupled products and interpretation of their biological activity. </p> <p>Considering the importance of the availability of THC derivatives in medicinal chemistry research and the fact that previously synthesized compounds were wrongly assigned, we feel this research is describing a straightforward pathway into new cannabinoids.</p>


2019 ◽  
Author(s):  
Miles Aukland ◽  
Mindaugas Šiaučiulis ◽  
Adam West ◽  
Gregory Perry ◽  
David Procter

<p>Aryl–aryl cross-coupling constitutes one of the most widely used procedures for the synthesis of high-value materials, ranging from pharmaceuticals to organic electronics and conducting polymers. The assembly of (hetero)biaryl scaffolds generally requires multiple steps; coupling partners must be functionalized before the key bond-forming event is considered. Thus, the development of selective C–H arylation processes in arenes, that side-step the need for prefunctionalized partners, is crucial for streamlining the construction of these key architectures. Here we report an expedient, one-pot assembly of (hetero)biaryl motifs using photocatalysis and two non-prefunctionalized arene partners. The approach is underpinned by the activation of a C–H bond in an arene coupling partner using the interrupted Pummerer reaction. A unique pairing of the organic photoredox catalyst and the intermediate dibenzothiophenium salts enables highly selective reduction in the presence of sensitive functionalities. The utility of the metal-free, one-pot strategy is exemplified by the synthesis of a bioactive natural product and the modification of complex molecules of societal importance.</p>


2021 ◽  
Vol 19 (9) ◽  
pp. 2000-2007
Author(s):  
Erin N. Welsh ◽  
Katherine N. Robertson ◽  
Alexander W. H. Speed

A one-pot double benzyne cascade allows rapid access to 1-substituted dibenzothiophene derivatives, including cross-coupling partners and a chiral amine.


2019 ◽  
Vol 21 (8) ◽  
pp. 1907-1911 ◽  
Author(s):  
Jian Xu ◽  
Mamatjan Arkin ◽  
Yongzhen Peng ◽  
Weihua Xu ◽  
Huilei Yu ◽  
...  

The first demonstration of photochemo-enzymatic whole-cell one-pot enantiocomplementary decarboxylative hydroxylation.


2019 ◽  
Vol 21 (3) ◽  
pp. 816-820 ◽  
Author(s):  
Takaoki Koyanagi ◽  
Ananda Herath ◽  
Ashley Chong ◽  
Maxim Ratnikov ◽  
Andrew Valiere ◽  
...  
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