Palladium-catalyzed aerobic regio- and stereo-selective olefination reactions of phenols and acrylatesviadirect dehydrogenative C(sp2)–O cross-coupling

2018 ◽  
Vol 54 (35) ◽  
pp. 4437-4440 ◽  
Author(s):  
Yun-Bin Wu ◽  
Dan Xie ◽  
Zhong-Lin Zang ◽  
Cheng-He Zhou ◽  
Gui-Xin Cai
Keyword(s):  
Oxidative Dehydrogenation ◽  
Palladium Catalyst ◽  
Cross Coupling ◽  
Palladium Catalyzed ◽  
Olefination Reactions

An efficient olefination protocol for the oxidative dehydrogenation of phenols and acrylates has been achieved using a palladium catalyst and O2as the sole oxidant.

scholarly journals Synergistic Palladium-Phosphoric Acid Catalysis in (3 + 2) Cycloaddition Reactions between Vinylcyclopropanes and Imines

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 150 ◽  
Author(s):  
Vasco Corti ◽  
Enrico Marcantonio ◽  
Martina Mamone ◽  
Alessandro Giungi ◽  
Mariafrancesca Fochi ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Palladium Catalyst ◽  
Palladium Catalysts ◽  
Acid Catalysis ◽  
Cycloaddition Reaction ◽  
Cross Coupling ◽  
Cycloaddition Reactions ◽  
Synergistic Catalysis ◽  
Palladium Catalyzed ◽  
First Time

The palladium-catalyzed (3 + 2) cycloaddition reaction between vinylcyclopropanes (VCPs) bearing geminal EWG’s and imines represents a straightforward and flexible entry to polysubstituted pyrrolidine derivatives. In this paper, we demonstrate that using a synergistic catalysis approach, based on the combination of phosphoric acid and palladium catalysts, it is possible to engage for the first time N-aryl and N-benzyl imines in this cycloaddition reaction. A range of polysubstituted pyrrolidines is obtained with moderate to good yields and diastereoselectivities, using a simple palladium species (Pd(PPh3)4) and an archetypical phosphoric acid as catalyst combination. A two-step scheme which exploits the same palladium catalyst for two consecutive and mechanistically distinct reactions (the cycloaddition and a Suzuki–Miyaura cross-coupling) is also presented. This synergistic catalysis approach is well posited for the development of the enantioselective version of this reaction. A screening of common BINOL-derived chiral phosphoric acids as catalyst component identified a species giving the product with moderate, yet promising, enantioselectivity (64% ee).

Palladium-catalyzed direct reductive cross-coupling of aryltrimethylammonium salts with aryl bromides

2021 ◽  
Author(s):  
Chen Zhang ◽  
Na-Na Ma ◽  
Zi-Lun Yu ◽  
Chuanji Shen ◽  
Xiaocong Zhou ◽  
...  
Keyword(s):  
Palladium Catalyst ◽  
Cross Coupling ◽  
Aryl Bromides ◽  
Palladium Catalyzed

An efficient palladium-catalyzed direct reductive cross-coupling of aryltrimethylammonium salts with aryl bromides was developed. The reactions proceeded smoothly in the presence of palladium catalyst, magnesium turnings, LiCl, and TMEDA in...

scholarly journals Recent Developments in the Suzuki–Miyaura Reaction Using Nitroarenes as Electrophilic Coupling Reagents

Catalysts ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 213 ◽  
Author(s):  
Lou Rocard ◽  
Piétrick Hudhomme
Keyword(s):  
Organic Synthesis ◽  
Palladium Catalyst ◽  
Recent Progress ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Coupling Reagents ◽  
Cross Coupling Reactions ◽  
Recent Developments ◽  
Palladium Catalyzed ◽  
Intense Research

Palladium-catalyzed cross-coupling reactions are nowadays essential in organic synthesis for the construction of C–C, C–N, C–O, and other C-heteroatom bonds. The 2010 Nobel Prize in Chemistry to Richard F. Heck, Ei-ichi Negishi, and Akira Suzuki was awarded for the discovery of these reactions. These great advances for organic chemists stimulated intense research efforts worldwide dedicated to studying these reactions. Among them, the Suzuki–Miyaura coupling (SMC) reaction, which usually involves an organoboron reagent and an organic halide or triflate in the presence of a base and a palladium catalyst, has become, in the last few decades, one of the most popular tools for the creation of C–C bonds. In this review, we present recent progress concerning the SMC reaction with the original use of nitroarenes as electrophilic coupling partners reacting with the organoboron reagent.

Suzuki–Miyaura cross-coupling for chemoproteomic applications

2020 ◽  
Author(s):  
Jian Cao ◽  
Ernest Armenta ◽  
Lisa Boatner ◽  
Heta Desai ◽  
Neil Chan ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Cross Coupling ◽  
Protein Profiling ◽  
Protein Labeling ◽  
Caspase 8 ◽  
Complex Cell ◽  
Bioorthogonal Chemistry ◽  
Reaction Conditions ◽  
Target Deconvolution ◽  
Palladium Catalyzed

Bioorthogonal chemistry is a mainstay of chemoproteomic sample preparation workflows. While numerous transformations are now available, chemoproteomic studies still rely overwhelmingly on copper-catalyzed azide –alkyne cycloaddition (CuAAC) or 'click' chemistry. Here we demonstrate that gel-based activity-based protein profiling (ABPP) and mass-spectrometry-based chemoproteomic profiling can be conducted using Suzuki–Miyaura cross-coupling. We identify reaction conditions that proceed in complex cell lysates and find that Suzuki –Miyaura cross-coupling and CuAAC yield comparable chemoproteomic coverage. Importantly, Suzuki–Miyaura is also compatible with chemoproteomic target deconvolution, as demonstrated using structurally matched probes tailored to react with the cysteine protease caspase-8. Uniquely enabled by the observed orthogonality of palladium-catalyzed cross-coupling and CuAAC, we combine both reactions to achieve dual protein labeling.

Dual Nickel/Palladium-Catalyzed Reductive Cross-Coupling Reactions Between Two Phenol Derivatives

2020 ◽  
Author(s):  
Baojian Xiong ◽  
Yue Li ◽  
Yin Wei ◽  
Søren Kramer ◽  
Zhong Lian
Keyword(s):  
Functional Group ◽  
Low Cost ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Phenol Derivatives ◽  
Cross Coupling Reactions ◽  
Palladium Catalyzed ◽  
One Step ◽  
Aryl Tosylates ◽  
Low Sensitivity

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.

Ferromagnetic Chain Based on Verdazyl-Nitroxide Diradical

2020 ◽  
Author(s):  
Evgeny Tretyakov ◽  
Svetlana Zhivetyeva ◽  
Pavel Petunin ◽  
Dmitry Gorbunov ◽  
Nina Gritsan ◽  
...  
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Ferromagnetic Coupling ◽  
Nitronyl Nitroxide ◽  
Triplet Ground State ◽  
One Dimensional ◽  
Cross Coupling Reaction ◽  
Palladium Catalyzed ◽  
Ferromagnetic Chain ◽  
High Yields

<p>Verdazyl-nitroxide diradicals were synthesized using the palladium-catalyzed cross-coupling reaction of the corresponding iodoverdazyls with a nitronyl nitroxide-2-ide gold(I) complex with high yields (up to 82%). The synthesized diradicals were found to be highly thermally stable and have a singlet (D<i>E</i><sub>ST</sub> » -64 cm<sup>–1</sup>) or triplet ground state (D<i>E</i><sub>ST</sub> ³ 25 and 100 cm<sup>–1</sup>), depending on which canonical hydrocarbon diradical type they belong to. Upon crystallization, triplet diradicals form unique one-dimensional (1D) spin <i>S</i> = 1 chains of organic diradicals with intrachain ferromagnetic coupling of <i>J</i>′/<i>k</i><sub>B</sub> from 3 to 6 K.</p>

Formal Total Syntheses of Crocacin A-D

2005 ◽  
Vol 70 (10) ◽  
pp. 1696-1708 ◽  
Author(s):  
Magnus Besev ◽  
Christof Brehm ◽  
Alois Fürstner
Keyword(s):  
Natural Products ◽  
Aldol Reaction ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Total Syntheses ◽  
Cross Coupling Reactions ◽  
Palladium Catalyzed ◽  
The Common ◽  
Selective Addition

A concise route to the common polyketide fragment5of crocacin A-D (1-4) is presented which has previously been converted into all members of this fungicidal and cytotoxic family of dipeptidic natural products by various means. Our synthesis features asyn-selective titanium aldol reaction controlled by a valinol-derived auxiliary, a zinc-mediated, palladium-catalyzedanti-selective addition of propargyl mesylate10to the chiral aldehyde9, as well as a comparison of palladium-catalyzed Stille and Suzuki cross-coupling reactions for the formation of the diene moiety of the target.

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