Direct reduction of unactivated alkyl halides for C(sp3)-N couplings under mild conditions presents a significant challenge in organic synthesis due to their low reduction potential. Herein, we introduce an in situ formed pyridyl-carbene-ligated copper (I) catalyst that is capable of abstracting halide atom and generating alkyl radicals for general C(sp3)-N couplings under visible light. Control experiments confirmed that the mono-pyridyl-carbene-ligated copper complex is the active species responsible for catalysis. Mechanistic investigations using transient absorption spectroscopy across multiple decades of timescales revealed ultrafast intersystem crossing (260 ps) of the photoexcited copper (I) complexes into their long-lived triplet excited states (>2 μs). The non-Stern-Volmer quenching dynamics of the triplets by unactivated alkyl halides suggests an association between copper (I) complexes and alkyl halides, thereby facilitating the abstraction of halide atoms via inner-sphere single electron transfer (SET), rather than outer-sphere SET, for the formation of alkyl radicals for subsequent cross couplings.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC11226431PMC
http://dx.doi.org/10.1038/s41467-024-50082-wDOI Listing

Publication Analysis

Top Keywords

alkyl halides
16
unactivated alkyl
12
csp3-n couplings
12
halide atom
8
general csp3-n
8
alkyl radicals
8
copper complexes
8
alkyl
6
situ copper
4
copper photocatalysts
4

Similar Publications

Hydroalkylation of terminal alkynes is a powerful approach to the synthesis of disubstituted alkenes. However, its application is largely unexplored in the synthesis of α,β-unsaturated carbonyls, which are common among synthetic intermediates and biologically active molecules. The thermodynamically less stable -isomers of activated alkenes have been particularly challenging to access because of their propensity for isomerization and the paucity of reliable -selective hydroalkylation methods.

View Article and Find Full Text PDF

Visible-Light-Induced Radical Carbon Oximation of Styrenes Using -Nitrosoamine and Organic Halides.

J Org Chem

December 2024

Jiangxi Province Key Laboratory of Natural and Biomimetic Drugs Research, College of Chemistry and Materials, Jiangxi Normal University, Nanchang, Jiangxi 330022, P. R. China.

An efficient visible-light-induced radical carbon oximation of styrenes with 1-nitrosopyrrolidine and organic halides is developed. The reaction proceeds smoothly in the absence of a transition metal and a photocatalyst under mild conditions, producing a wide range of functionalized oximes in moderate to good yields. Mechanistic studies reveal that the reaction involves the generation of nucleophilic α-amino alkyl radicals and subsequent halogen atom transfer (XAT) with organic halides.

View Article and Find Full Text PDF

Facile Synthesis of Functional Polytrithiocarbonates from Multicomponent Tandem Polymerizations of CS, Thiols, and Alkyl Halides.

J Am Chem Soc

December 2024

Shenzhen Institute of Aggregate Science and Technology, School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, China.

Polytrithiocarbonates have attracted significant attention recently because of their good thermal stability, light refractivity, crystallinity, and mechanical properties; however, the exploration of their structures and functionalities has been limited by their synthetic approaches. Multicomponent polymerization featuring simple monomers, mild conditions, diversified product structures, and high efficiency could provide a powerful and versatile tool to synthesize various polytrithiocarbonates from commercially available monomers. Herein, a robust and efficient multicomponent tandem polymerization (MCTP) of CS, dithiols, and alkyl halides was developed in DMF with KCO at room temperature in air to synthesize 12 polytrithiocarbonates with diversified and systematically tuned structures, high molecular weights (s up to 37900 g/mol), and high yields (up to 93%).

View Article and Find Full Text PDF

We disclose a broad platform for copper-catalyzed atom transfer radical addition (ATRA) of electron-deficient olefins. Catalytic Cu(dtbbpy)(OTf) enables radical addition of electron-deficient alkyl halides to acrylates, acrylamides, and vinyl sulfones in fair to excellent yields. The resultant ATRA products can be used in a variety of telescoped reactions, including substitution with basic amine nucleophiles to afford α-amino esters.

View Article and Find Full Text PDF

Efficient catalytic systems for various organic transformations in green solvents, especially water, are in great demand. Catalytically active bis-NHC complexes of palladium(II) based on imidazole-4,5-dicarboxylic acid with different lipophilicities were obtained. The synthesis of imidazolium salts was complicated by the formation of side products of nucleophilic substitution by iodide ions in the Menshutkin reaction involving alkyl iodides, which was successfully resolved by using alkyl tosylates.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!