Palladium catalyzed cross-coupling reactions of difunctional derivatives Bu3SnArBr. Synthesis of regioregular poly(3-alkylthiophenes) and poly(4-alkyl 2,2'-bithiophenes) with high molecular weights

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.

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Formal Total Syntheses of Crocacin A-D

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20051696 ◽

2005 ◽

Vol 70 (10) ◽

pp. 1696-1708 ◽

Cited By ~ 12

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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Base-Free Synthesis and Synthetic Application of Novel 3-(organochalcogenyl)prop-2-yn-1-yl Esters: Promising Anticancer Agents

Synthesis ◽

10.1055/a-1477-6470 ◽

2021 ◽

Author(s):

Fabiane Gritzenco ◽

Jean Carlo Kazmierczak ◽

Thiago Anjos ◽

Adriane Sperança ◽

Maura Luise Bruckchem Peixoto ◽

...

Keyword(s):

Anticancer Agents ◽

Cross Coupling ◽

Coupling Reactions ◽

Chalcogen Bond ◽

Cross Coupling Reactions ◽

Air Atmosphere ◽

Carbon Carbon Bonds ◽

Palladium Catalyzed ◽

Synthetic Application

This manuscript portrays the CuI-catalyzed Csp-chalcogen bond formation through cross-coupling reactions of propynyl esters and diorganyl dichalcogenides by using DMSO as solvent, at room temperature, under base-free and open-to-air atmosphere. Generally, the reactions have proceeded very smoothly, being tolerant to range of substituents present in both substrates, affording the novel 3-(organochalcogenyl)prop-2-yn-1-yl esters in moderate to good yields. Noteworthy, the 3-(butylselanyl)prop-2-yn-1-yl benzoate proved to be useful as synthetic precursor in palladium-catalyzed Suzuki and Sonogashira type cross-coupling reactions by replacing the carbon-chalcogen bond by new carbon-carbon bonds. Moreover, the 3-(phenylselanyl)prop-2-yn-1-yl benzoate has shown promising in vitro activity against glioblastoma cancer cells.

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