Porphyrinic assemblies of pyridine-containing macrocycles

2005 ◽  
Vol 09 (11) ◽  
pp. 794-802 ◽  
Author(s):  
Katie Campbell ◽  
Robert McDonald ◽  
Rik R. Tykwinski
Keyword(s):  
Electronic Properties ◽  
Cross Coupling ◽  
Palladium Catalyzed ◽  
Ruthenium Porphyrin

Using a combination of palladium-catalyzed cross-coupling and copper-catalyzed homocoupling reactions, two pyridine-containing macrocycles with varying pendant substitution were constructed. Their synthesis and subsequent coordination to a ruthenium porphyrin is described. In addition to synthetic details and characterization, an examination of their electronic properties is provided.

Sterically Demanding, Sulfonated, Triarylphosphines: Application to Palladium-Catalyzed Cross-Coupling, Steric and Electronic Properties, and Coordination Chemistry

2008 ◽  
Vol 27 (4) ◽  
pp. 576-593 ◽  
Author(s):  
Lucas R. Moore ◽  
Elizabeth C. Western ◽  
Raluca Craciun ◽  
Jason M. Spruell ◽  
David A. Dixon ◽  
...  
Keyword(s):  
Coordination Chemistry ◽  
Electronic Properties ◽  
Cross Coupling ◽  
Sterically Demanding ◽  
Palladium Catalyzed

Palladium-Catalyzed C–P Cross-Coupling between (Het)aryl Halides and Secondary Phosphine Oxides

Synthesis ◽  
2019 ◽  
Vol 51 (11) ◽  
pp. 2379-2386 ◽  
Author(s):  
Gladis Zakirova ◽  
Dmitrii Mladentsev ◽  
Nataliya Borisova
Keyword(s):  
Electronic Properties ◽  
Heterocyclic Compounds ◽  
Cross Coupling ◽  
Secondary Phosphine ◽  
Phosphine Oxides ◽  
Tertiary Phosphine ◽  
Reaction Conditions ◽  
Efficient Procedure ◽  
Palladium Catalyzed ◽  
Tertiary Alkyl

An efficient procedure for C–P bond formation via the palladium-catalyzed [Pd(OAc)2/dppf/Cs2CO3] reaction between dichloroheterocycles and secondary phosphine oxides was developed. The steric and electronic properties of substituents were varied to establish the scope and limitations of the method developed. By applying these conditions, a variety of new heterocyclic compounds bearing two tertiary phosphine oxides were successfully synthesized in moderate to excellent yields. After adjustments to the reaction conditions [Pd(OAc)2/dippf/t-BuOK], cross-coupling of secondary phosphine oxides with bulky (secondary or tertiary alkyl) substituents on the phosphorus atom was achieved. Extension of the methodology to monohalohetarenes and monohaloarenes was successfully carried out; once again, the steric and electronic properties of the halides were varied widely. The desired reaction occurred in all cases studied, giving high to excellent yields of product regardless of the nature and positions of substituents.

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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