Alkynes are amongst the most valuable functional groups in organic chemistry and widely used in chemical biology, pharmacy, and materials science. However, the preparation of alkyl-substituted alkynes still remains elusive. Here, we show a nickel-catalyzed deaminative Sonogashira coupling of alkylpyridinium salts. Key to the success of this coupling is the development of an easily accessible and bench-stable amide-type pincer ligand. This ligand allows naturally abundant alkyl amines as alkylating agents in Sonogashira reactions, and produces diverse alkynes in excellent yields under mild conditions. Salient merits of this chemistry include broad substrate scope and functional group tolerance, gram-scale synthesis, one-pot transformation, versatile late-stage derivatizations as well as the use of inexpensive pre-catalyst and readily available substrates. The high efficiency and strong practicability bode well for the widespread applications of this strategy in constructing functional molecules, materials, and fine chemicals.

The direct iminoalkynylation of unactivated olefins with terminal alkynes is achieved for the first time by nickel-catalyzed cascade iminyl-radical cyclization/Sonogashira-type coupling of γ,δ-unsaturated oxime esters under mild conditions. This transformation...

Herein, we report a general and practical nickel-catalyzed deaminative allenylation of amino acid derivatives with terminal alkynes. The well-designed, electron deficient, and sterically hindered amide-type NN 2 pincer ligand was crucial to the success of this transformation, enabling the coupling to occur under mild conditions with high efficiency. The remarkable features of this chemistry are its good scalability, its broad substrate scope, functional group tolerance, and the efficient modification of peptides, drugs, and natural products.

Herein, we disclose a general and practical iminoarylation of alkenes by nickel-catalyzed reductive cross-coupling of unsaturated oxime esters with readily available aryl halides, providing an expedient approach for constructing pyrroline derivatives. The absence of organometallic reagents enables the reaction to occur under mild conditions with a broad substrate scope and good functional group tolerance. Moreover, other C-based electrophiles, including alkenyl, alkynyl and alkyl halides, or pseudohalides, were also competent substrates for this reaction.

Alkynes are amongst the most valuable functional groups in organic chemistry and widely used in chemical biology, pharmacy, and materials science. However, the preparation of alkyl-substituted alkynes still remains elusive. Herein, a novel transformation is disclosed that enables the coupling of terminal alkynes with alkylpyridinium salts under Ni-catalysis. Key to the success of this coupling was the development of a new and readily accessible amide-type pincer ligand. This ligand allows naturally abundant alkyl amines as alkylating agents in Sonogashira reactions for the first time, and leads to diverse alkynes in excellent yields under mild conditions. Salient merits of this chemistry include broad substrates scope and functional group tolerance, gram-scale synthesis, one-pot transformation, versatile late-stage derivatizations as well as the use of inexpensive pre-catalyst and readily available substrates. The high efficiency and strong practicability bode well for the widespread applications of this strategy in constructing functional molecules, materials, and fine chemicals.