CuLi2Cl4 catalysed cross-coupling strategy for the formal synthesis of the diterpenoid (+)-subersic acid from (–)-sclareol

2017 ◽  
Vol 41 (7) ◽  
pp. 394-397 ◽  
Author(s):  
Qiangyong Wu ◽  
Peiqiang Wang ◽  
Bin Zhou ◽  
Sikai Hua ◽  
Jiangmeng Ren ◽  
...  
Keyword(s):  
Functional Group ◽  
Cross Coupling ◽  
Hydroxybenzoic Acid ◽  
Formal Synthesis ◽  
Coupling Strategy

A CuLi2Cl4-catalysed regioselective cross-coupling is used in a key step leading to the concise synthesis of (+)-subersic acid with an overall yield of 25.7% from commercially available (–)-sclareol. The coupled product 15-(2-methoxy-5-carbomethoxy)phenyl-labda-8(9),13 E-diene was obtained in 62% yield under CuLi2Cl4 conditions starting from 2-iodo-4-carbomethoxyanisole and 15-acetoxy-labda-8(9),13 E-diene. These were derived from 4-hydroxybenzoic acid and (–)-sclareol respectively. The 15-(2-methoxy-5-carbomethoxy)phenyl-labda-8(9),13 E-diene was easily transformed into (+)-subersic acid by demethylation of the phenol ether and ester. This cross-coupling strategy showed a good functional group tolerance and various (+)-subersic acid derivatives were obtained in moderate yields.

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.

scholarly journals Protecting group-free, selective cross-coupling of alkyltrifluoroborates with borylated aryl bromides via photoredox/nickel dual catalysis

2015 ◽  
Vol 112 (39) ◽  
pp. 12026-12029 ◽  
Author(s):  
Yohei Yamashita ◽  
John C. Tellis ◽  
Gary A. Molander
Keyword(s):  
Small Molecules ◽  
Functional Group ◽  
Cross Coupling ◽  
Differential Protection ◽  
Coupling Reactions ◽  
Protecting Group ◽  
Cross Coupling Reactions ◽  
Aryl Bromides ◽  
Rapid Construction ◽  
Metal Catalyzed

Orthogonal reactivity modes offer substantial opportunities for rapid construction of complex small molecules. However, most strategies for imparting orthogonality to cross-coupling reactions rely on differential protection of reactive sites, greatly reducing both atom and step economies. Reported here is a strategy for orthogonal cross-coupling wherein a mechanistically distinct activation mode for transmetalation of sp3-hybridized organoboron reagents enables C-C bond formation in the presence of various protected and unprotected sp2-hybridized organoborons. This manifold has the potential for broad application, because orthogonality is inherent to the activation mode itself. The diversification potential of this platform is shown in the rapid elaboration of a trifunctional lynchpin through various transition metal-catalyzed processes without nonproductive deprotection or functional group manipulation steps.

Stereodivergent Hydrosilylation, Hydrostannylation, and Hydrogermylation of α-Trifluoromethylated Alkynes and Their Synthetic Applications

Synthesis ◽  
2016 ◽  
Vol 48 (19) ◽  
pp. 3317-3330 ◽  
Author(s):  
Cédric Tresse ◽  
Stéphane Schweizer ◽  
Philippe Bisseret ◽  
Jacques Lalevée ◽  
Gwilherm Evano ◽  
...  
Keyword(s):  
Functional Group ◽  
Cross Coupling ◽  
Aryl Halides ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Palladium Catalyzed

Stereoselective hydrometalation reactions of aryl- and alkyl-substituted trifluoromethylated alkynes with triethylsilane, tributylstannane, and triphenylgermane have been investigated. (E)-α-CF3-Vinylsilanes, -stannanes, and -germanes were obtained under palladium-catalyzed conditions whereas the corresponding (Z)-α-CF3-vinylgermanes were obtained under radical conditions. These reactions proceed in good to excellent yields and possess a broad functional group tolerance. Applications of the (Z)- and (E)-α-CF3-vinylgermanes in palladium-catalyzed cross-coupling reactions with aryl halides having diverse electronic requirements were also investigated. The corresponding (Z)- and (E)-α-CF3-styrenes were obtained as single isomers, thus demonstrating the utility of these versatile synthons for the synthesis of stereodefined trifluoromethylated alkenes.

A biaryl cross-coupling strategy for functionalisation of benzocrown ethers

2007 ◽  
pp. 3565 ◽  
Author(s):  
Sally Dixon ◽  
Richard C. D. Brown ◽  
Philip A. Gale
Keyword(s):  
Cross Coupling ◽  
Benzocrown Ethers ◽  
Coupling Strategy

Retaining Alkyl Nucleophile Regiofidelity in Transition-Metal-Mediated Cross-Couplings to Aryl Electrophiles

Synthesis ◽  
2018 ◽  
Vol 50 (20) ◽  
pp. 3974-3996 ◽  
Author(s):  
Josep Cornella ◽  
Matthew O’Neill
Keyword(s):  
Transition Metal ◽  
Functional Group ◽  
Chemical Space ◽  
Cross Coupling ◽  
Transition Metal Catalysis ◽  
Metal Catalysis ◽  
Substantial Progress ◽  
Tertiary Alkyl ◽  
Metal Ligand

While the advent of transition-metal catalysis has undoubtedly transformed synthetic chemistry, problems persist with the introduction of secondary and tertiary alkyl nucleophiles into C(sp2) aryl electrophiles. Complications arise from the delicate organometallic intermediates typically invoked by such processes, from which competition between the desired reductive elimination event and the deleterious β-H elimination pathways can lead to undesired isomerization of the incoming nucleophile. Several methods have integrated distinct combinations of metal, ligand, nucleophile, and electrophile to provide solutions to this problem. Despite substantial progress, refinements to current protocols will facilitate the realization of complement reactivity and improved functional group tolerance. These issues have become more pronounced in the context of green chemistry and sustainable catalysis, as well as by the current necessity to develop robust, reliable cross-couplings beyond less explored C(sp2)–C(sp2) constructs. Indeed, the methods discussed herein and the elaborations thereof enable an ‘unlocking’ of accessible topologically enriched chemical space, which is envisioned to influence various domains of application.1 Introduction2 Mechanistic Considerations3 Magnesium Nucleophiles4 Zinc Nucleophiles5 Boron Nucleophiles6 Other Nucleophiles7 Tertiary Nucleophiles8 Reductive Cross-Coupling with in situ Organometallic Formation9 Conclusion

Electrochemical and direct C–H methylthiolation of electron-rich aromatics

2020 ◽  
Vol 22 (15) ◽  
pp. 4906-4911
Author(s):  
Yaxing Wu ◽  
Hongliang Ding ◽  
Ming Zhao ◽  
Zhong-Hai Ni ◽  
Jing-Pei Cao
Keyword(s):  
Cross Coupling ◽  
Coupling Strategy

The electrochemical-induced C–H methylthiolation of electron-rich aromatics has been accomplished via a three component cross-coupling strategy.

scholarly journals Iron-Catalyzed C(sp2)–C(sp3) Cross-Coupling of Aryl Chlorobenzoates with Alkyl Grignard Reagents

Molecules ◽  
2020 ◽  
Vol 25 (1) ◽  
pp. 230 ◽  
Author(s):  
Elwira Bisz ◽  
Michal Szostak
Keyword(s):  
Organic Synthesis ◽  
Nucleophilic Addition ◽  
Functional Group ◽  
High Selectivity ◽  
Cross Coupling ◽  
Environmentally Benign ◽  
Grignard Reagents ◽  
High Importance ◽  
Iron Salts ◽  
The Cross

Aryl benzoates are compounds of high importance in organic synthesis. Herein, we report the iron-catalyzed C(sp2)–C(sp3) Kumada cross-coupling of aryl chlorobenzoates with alkyl Grignard reagents. The method is characterized by the use of environmentally benign and sustainable iron salts for cross-coupling in the catalytic system, employing benign urea ligands in the place of reprotoxic NMP (NMP = N-methyl-2-pyrrolidone). It is notable that high selectivity for the cross-coupling is achieved in the presence of hydrolytically-labile and prone to nucleophilic addition phenolic ester C(acyl)–O bonds. The reaction provides access to alkyl-functionalized aryl benzoates. The examination of various O-coordinating ligands demonstrates the high activity of urea ligands in promoting the cross-coupling versus nucleophilic addition to the ester C(acyl)–O bond. The method showcases the functional group tolerance of iron-catalyzed Kumada cross-couplings.

scholarly journals Double Heck Route to a Dibenzoxepine and Convergent Suzuki Cross-Coupling Strategy for the Synthesis of an MR Antagonist

2017 ◽  
Vol 21 (2) ◽  
pp. 208-217 ◽  
Author(s):  
Marvin M. Hansen ◽  
Neil J. Kallman ◽  
Thomas M. Koenig ◽  
Ryan J. Linder ◽  
Rachel N. Richey ◽  
...  
Keyword(s):  
Cross Coupling ◽  
Coupling Strategy
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