scholarly journals Novel Diketopyrrolopyrrole-Based π-Conjugated Molecules Synthesized Via One-Pot Direct Arylation Reaction

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1760 ◽  
Author(s):  
Hui Liu ◽  
Xiao-Feng Zhang ◽  
Jing-Zhao Cheng ◽  
Ai-Guo Zhong ◽  
He-Rui Wen ◽  
...  

Diketopyrrolopyrrole (DPP) is an important type of π-conjugated building block for high-performance organic electronic materials. DPP-based conjugated materials are usually synthesized via Suzuki, Stille, or Negishi cross-coupling reactions, which require organometallic precursors. In this paper, a series of novel phenyl-cored DPP molecules, including five meta-phenyl-cored molecules and four para-phenyl-cored molecules, have been synthesized in moderate to good yields, in a facile manner, through the Pd-catalyzed direct arylation of C–H bonds, and their optoelectrical properties have been investigated in detail. All new molecules have been fully characterized by NMR, MALDI-TOF MS, elemental analysis, UV–visible spectroscopy, and cyclic voltammetry. This synthetic strategy has evident advantages of atom- and step-economy and low cost, compared with traditional cross-coupling reactions.

2020 ◽  
Author(s):  
Baojian Xiong ◽  
Yue Li ◽  
Yin Wei ◽  
Søren Kramer ◽  
Zhong Lian

Cross-coupling between substrates that can be easily derived from phenols is highly attractive due to the abundance and low cost of phenols. Here, we report a dual nickel/palladium-catalyzed reductive cross-coupling between aryl tosylates and aryl triflates; both substrates can be accessed in just one step from readily available phenols. The reaction has a broad functional group tolerance and substrate scope (>60 examples). Furthermore, it displays low sensitivity to steric effects demonstrated by the synthesis of a 2,2’disubstituted biaryl and a fully substituted aryl product. The widespread presence of phenols in natural products and pharmaceuticals allow for straightforward late-stage functionalization, illustrated with examples such as Ezetimibe and tyrosine. NMR spectroscopy and DFT calculations indicate that the nickel catalyst is responsible for activating the aryl triflate, while the palladium catalyst preferentially reacts with the aryl tosylate.


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>


Science ◽  
2019 ◽  
Vol 364 (6439) ◽  
pp. eaav9713 ◽  
Author(s):  
Asik Hossain ◽  
Aditya Bhattacharyya ◽  
Oliver Reiser

Visible-light photoredox catalysis offers a distinct activation mode complementary to thermal transition metal catalyzed reactions. The vast majority of photoredox processes capitalizes on precious metal ruthenium(II) or iridium(III) complexes that serve as single-electron reductants or oxidants in their photoexcited states. As a low-cost alternative, organic dyes are also frequently used but in general suffer from lower photostability. Copper-based photocatalysts are rapidly emerging, offering not only economic and ecological advantages but also otherwise inaccessible inner-sphere mechanisms, which have been successfully applied to challenging transformations. Moreover, the combination of conventional photocatalysts with copper(I) or copper(II) salts has emerged as an efficient dual catalytic system for cross-coupling reactions.


2020 ◽  
Vol 11 (37) ◽  
pp. 10236-10242
Author(s):  
Yukun Cheng ◽  
Channing K. Klein ◽  
Ian A. Tonks

Multisubstituted pyrroles are commonly found in many bioactive small molecule scaffolds, yet the synthesis of highly-substituted pyrrole cores remains challenging.


2017 ◽  
Vol 15 (48) ◽  
pp. 10289-10298 ◽  
Author(s):  
Kapil Mohan Saini ◽  
Rakesh K. Saunthwal ◽  
Akhilesh K. Verma

Unsymmetrical one-pot sequential cross-coupling reactions of sterically hindered tetrabromothiophene with arylboronic acid and an alkyne/alkene to afford selective bi-, tri-, and tetrasubstituted aryl/alkynyl-thiophenes with the aid of a palladium catalyst were described.


ChemInform ◽  
2013 ◽  
Vol 44 (52) ◽  
pp. no-no
Author(s):  
Muhammad Farooq Ibad ◽  
Dhafer Saber Zinad ◽  
Munawar Hussain ◽  
Asad Ali ◽  
Alexander Villinger ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document