Three-Coordinate Copper(II) Alkynyl Complex in C–C Bond Formation: The Sesquicentennial of the Glaser Coupling DOI
Abolghasem Bakhoda, Otome E. Okoromoba,

Christine Greene

et al.

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(43), P. 18483 - 18490

Published: Sept. 21, 2020

Copper(II) alkynyl species are proposed as key intermediates in numerous Cu-catalyzed C-C coupling reactions. Supported by a β-diketiminate ligand, the three-coordinate copper(II) [CuII]-C≡CAr (Ar = 2,6-Cl2C6H3) forms upon reaction of alkyne H-C≡CAr with tert-butoxide complex [CuII]-OtBu. In solution, this cleanly transforms to Glaser product ArC≡C-C≡CAr and [CuI](solvent). Addition nucleophiles R'C≡C-Li (R' aryl, silyl) Ph-Li affords corresponding Csp-Csp Csp-Csp2 coupled products RC≡C-C≡CAr Ph-C≡CAr concomitant generation [CuI](solvent) {[CuI]-C≡CAr}-, respectively. density functional theory (DFT) calculations, redox disproportionation [CuIII](C≡CAr)(R) that reductively eliminate R-C≡CAr products. also captures trityl radical Ph3C· give Ph3C-C≡CAr. Radical capture represents Csp-Csp3 bond-forming step copper-catalyzed C-H functionalization benzylic substrates R-H alkynes H-C≡CR' (hetero)aryl, provide R-C≡CR via relay tBuOOtBu oxidant.

Language: Английский

Distal Ruthenaelectro‐Catalyzed meta‐C−H Bromination with Aqueous HBr DOI
Yulei Wang, Hendrik Simon, Xinran Chen

et al.

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(20)

Published: Feb. 16, 2022

While electrochemical ortho-selective C-H activations are well established, distal continue to be underdeveloped. In contrast, we herein describe the meta-C-H functionalization. The remote bromination was accomplished in an undivided cell by RuCl

Language: Английский

Citations

34
Remote C−H Glycosylation by Ruthenium(II) Catalysis: Modular Assembly ofmeta‐C‐Aryl Glycosides DOI
Jun Wu, Nikolaos Kaplaneris,

Julia Pöhlmann

et al.

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(42)

Published: July 25, 2022

Abstract The prevalence of C ‐aryl glycosides in biologically active natural products and approved drugs has long motivated the development efficient strategies for their selective synthesis. Cross‐couplings have been frequently used, but largely relied on palladium catalyst with prefunctionalized substrates, while ruthenium‐catalyzed glycoside preparation thus far proven elusive. Herein, we disclose a versatile ruthenium(II)‐catalyzed meta ‐C−H glycosylation to access ‐ from readily available glycosyl halide donors. robustness ruthenium catalysis was reflected by mild reaction conditions, outstanding levels anomeric selectivity exclusive ‐site‐selectivity.

Language: Английский

Citations

29
The crucial role of silver(i)-salts as additives in C–H activation reactions: overall analysis of their versatility and applicability DOI Creative Commons
Renato L. Carvalho, Emilay B. T. Diogo, Simon L. Homölle

et al.

Chemical Society Reviews, Journal Year: 2023, Volume and Issue: 52(18), P. 6359 - 6378

Published: Jan. 1, 2023

This review discusses the important role of silver( i ) salts as additives in transition-metal catalyzed C–H activation, and depicts discussion about current shift towards Ag-free procedures, plausible sustainable alternatives.

Language: Английский

Citations

21
Access to unsaturated bicyclic lactones by overriding conventional C(sp3)–H site selectivity DOI Creative Commons
Jayabrata Das, Wajid Ali, Animesh Ghosh

et al.

Nature Chemistry, Journal Year: 2023, Volume and Issue: 15(11), P. 1626 - 1635

Published: Aug. 10, 2023

Transition metal catalysis plays a pivotal role in transforming unreactive C-H bonds. However, regioselective activation of distal aliphatic bonds poses tremendous challenge, particularly the absence directing templates. Activation methylene bond presence methyl is underexplored. Here we show to form unsaturated bicyclic lactones. The protocol allows reversal general selectivity activation. Computational studies suggest that reversible followed by β-hydride elimination generate Pd-coordinated cycloalkene undergoes stereoselective C-O cyclization, and subsequent provide broad generality this reaction has been highlighted via dehydrogenative lactonization mid macro ring containing acids along with olefination olefin allyl alcohol. method substantially simplifies synthesis important lactones are features natural products as well pharmacoactive molecules.

Language: Английский

Citations

19
Three-Coordinate Copper(II) Alkynyl Complex in C–C Bond Formation: The Sesquicentennial of the Glaser Coupling DOI
Abolghasem Bakhoda, Otome E. Okoromoba,

Christine Greene

et al.

Journal of the American Chemical Society, Journal Year: 2020, Volume and Issue: 142(43), P. 18483 - 18490

Published: Sept. 21, 2020

Copper(II) alkynyl species are proposed as key intermediates in numerous Cu-catalyzed C-C coupling reactions. Supported by a β-diketiminate ligand, the three-coordinate copper(II) [CuII]-C≡CAr (Ar = 2,6-Cl2C6H3) forms upon reaction of alkyne H-C≡CAr with tert-butoxide complex [CuII]-OtBu. In solution, this cleanly transforms to Glaser product ArC≡C-C≡CAr and [CuI](solvent). Addition nucleophiles R'C≡C-Li (R' aryl, silyl) Ph-Li affords corresponding Csp-Csp Csp-Csp2 coupled products RC≡C-C≡CAr Ph-C≡CAr concomitant generation [CuI](solvent) {[CuI]-C≡CAr}-, respectively. density functional theory (DFT) calculations, redox disproportionation [CuIII](C≡CAr)(R) that reductively eliminate R-C≡CAr products. also captures trityl radical Ph3C· give Ph3C-C≡CAr. Radical capture represents Csp-Csp3 bond-forming step copper-catalyzed C-H functionalization benzylic substrates R-H alkynes H-C≡CR' (hetero)aryl, provide R-C≡CR via relay tBuOOtBu oxidant.

Language: Английский

Citations

46