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A visible light-induced Co-catalyzed highly regio- and stereoselective reductive coupling of vinyl azaarenes and alkynes has been developed. Notably, Hünig's base together with simple ethanol has been successfully applied as the hydrogen sources instead of commonly used Hantzsch esters in this catalytic photoredox reaction. This approach has considerable advantages for the straightforward synthesis of stereodefined multiple substituted alkenes bearing an azaarene motif, such as excellent regioselectivity (20 : 1 for30 examples) and stereoselectivity (20 : 1 E/Z), broad substrate scope and good functional group compatibility under mild reaction conditions, which has been utilized in the concise synthesis of natural product monomorine I. A reasonable catalytic reaction pathway involving protolysis of the cobaltacyclopentene intermediate has been proposed based on the mechanistic studies.

An atom- and step-economic intermolecular multi-component palladium-catalyzed C–H amidation of alkenes with carbon monoxide and organic azides has been developed for the synthesis of alkenyl amides. The reaction proceeds efficiently without an ortho-directing group on the alkene substrates. Nontoxic dinitrogen is generated as the sole by-product. Computational studies and control experiments have revealed that the reaction takes place via an unexpected mechanism by tandem palladium catalysis.

An efficient [3 + 1 + 1] cyclization of vinyl oxiranes for the synthesis of oxazolidinones has been developed via tandem palladium catalysis. This reaction provides an atom- and step-efficient strategy to produce oxazolidinones from readily available azides and carbon monoxide under mild additive- and base-free conditions. The mechanistic studies showed that the reaction occurred through an in situ generated isocyanate intermediate.

An atom- and step-economic multi-component cobalt-catalyzed synthesis of amidines has been reported by using amines, isocyanides, and diazo compounds as carbene sources. This protocol provides a synthetically simple, highly efficient strategy for the straightforward synthesis of functionalized amidines with a range of substrates.

The amide linkage is one of the most important structural moieties in both chemistry and biology. Here, we briefly discuss recent advances in catalytic intermolecular C–H carbonylation reactions for the synthesis of amides, with particular attention to our intermolecular C–H amidation of arenes with carbon monoxide and organic azides to produce amides.1 Introduction2 Representative Methods for Amide Synthesis3 C–H Aminocarbonylation with Carbon Monoxide and Amines4 C–H Amidation to Amides with Carbon Monoxide and Azides5 Summary and Outlook

An efficient Pd-catalyzed amidation of 1,3-diketones has been developed using carbon monoxide and organic azides. This reaction provides a step-economic approach to produce β-ketoamides from readily available compounds under mild ligand-, oxidant-, and base-free conditions. The mechanistic studies showed that the reaction occurred through an in situ generated isocyanate intermediate.

We report here a Ni-catalyzed reductive coupling of aldehydes with widely available 1,3-dienes under visible-light photoredox dual catalysis. The homoallyic alcohols are obtained in broad scope wit...

Amide bond formation is one of the most important reactions in organic chemistry because of the widespread presence of amides in pharmaceuticals and biologically active compounds. Existing methods for amides synthesis are reaching their inherent limits. Described herein is a novel rhodium-catalyzed three-component reaction to synthesize amides from organic azides, carbon monoxide, and (hetero)arenes via nitrene-intermediates and direct C-H functionalization. Notably, the reaction proceeds in an intermolecular fashion with N2 as the only by-product, and either directing groups nor additives are required. The computational and mechanistic studies show that the amides are formed via a key Rh-nitrene intermediate.

An efficient Pd-catalyzed amidation of 1,3-diketones has been developed using carbon monoxide and organic azides. This reaction provides a step-economic approach to produce β-ketoamides from readily available compounds under mild ligand-, oxidant-, and base-free conditions. The mechanistic studies showed that the reaction occurred through an in situ generated isocyanate intermediate.

A Co(II)/Ag(I) synergistically catalyzed three-component reaction of isocyanide with terminal alkyne and water to afford alkynamide derivatives is reported. The insertion of monoisocyanide into the C–H bond of terminal alkynes is an efficient, straightforward, atom-economical route to alkynamides, which are useful synthons in organic synthesis. This synergistic process achieves the cleavage of a C–H bond and the construction of new C–C and C═O bonds under mild conditions through the reaction of Co(II)-activated isocyanides and a Ag(I)-complex-activated terminal alkyne. This reaction has broad substrate versatility and functional group tolerance.

A Co(II)-catalyzed isocyanide insertion reaction with sulfonyl azides in alcohols to form sulfonyl isoureas via nitrene intermediate has been developed. This protocol provides a new, environmentally friendly, and simple strategy for the synthesis of sulfonyl isourea derivatives by employing a range of substrates under mild conditions.

A Co(II)-catalyzed synthesis of sulfonyl guanidines by using amines, isonitriles, and organic azides as nitrene sources has been developed. This protocol provides an environmentally friendly and simple strategy for the synthesis of sulfonyl guanidine derivatives by employing a range of substrates and will find potential applications in organic synthesis. The computational and EPR studies suggested the formation of guanidine derivatives via a cobalt–nitrene radical intermediate.

A cobalt-catalyzed [4 + 1] cycloaddition of easily accessible amides with isocyanides for the efficient synthesis of 3-iminoisoindolinone derivatives in high yield under mild conditions via intramolecular C(sp2)–H activation and isocyanide insertion is reported. The annulation was found to be applicable to a broad range of substrates, including arylamides, heteroarylamides, and acrylamide derivatives. Strongly coordinating N-heterocyclic directing groups such as pyridine, pyrimidine, and even pyrazole were fully tolerated in this cobalt-catalyzed C–H activation reaction.

A Co(II)/Ag(I) synergistically catalyzed three-component reaction of isocyanide with terminal alkyne and water to afford alkynamide derivatives is reported. The insertion of monoisocyanide into the C-H bond of terminal alkynes is an efficient, straightforward, atom-economical route to alkynamides, which are useful synthons in organic synthesis. This synergistic process achieves the cleavage of a C-H bond and the construction of new C-C and C═O bonds under mild conditions through the reaction of Co(II)-activated isocyanides and a Ag(I)-complex-activated terminal alkyne. This reaction has broad substrate versatility and functional group tolerance.

A Co-catalyzed effective synthesis of N-sulfonylcarboxamides from the reaction of carboxylic acids and organic azides in the presence of isocyanide has been developed. The protocol has the advantages of short time, low temperature, and being oxidant-free, which provides a new and simple approach for the synthesis of N-sulfonylcarboxamides in good to excellent yields with a broad substrate scope.

A new strategy for the catalytic synthesis of the pyrrolo[2,3-b]quinoline skeleton by the reaction of isocyanides with (cyclopropylidene(aryl)methyl)aniline (amino-MCPs) is presented, taking advantage of I2/CHP mediated carbodiimide intermediate generation. This reaction involves three C–N bonds and one C–C bond generation under metal-free and azide-free conditions.

An efficient and practical synthesis of benzothiazine by K2S initiated sulfur insertion reaction with enaminones via electron catalysis is developed., An efficient and practical synthesis of benzothiazine by K2S initiated sulfur insertion reaction with enaminones via electron catalysis is developed. This protocol provides a new, environment-friendly and simple strategy to construct benzothiazine derivatives via formation of two C–S bonds under transition metal-free, additive-free and oxidant-free conditions. K2S not only provides the sulfur insertion source, but also ignites the reaction through the formation of a trisulfur radical anion and electrons in DMF.

A chemoselective palladium-catalyzed isocyanide insertion reaction of enaminones was developed. Amide derivatives were synthesized by this C–H functionalization and subsequent hydrolysis reactions. 4-Aminoquinoline derivatives were prepared by this C–H functionalization, which includes a 1,3-palladium migration in the process.

A chemoselective Co(II)-catalyzed effective synthesis of sulfonylamidyl amide and 3-imine indole derivatives by using isocyanides and sulfonyl azides has been developed. This protocol provides a new, environmentally friendly and simple strategy for the efficient synthesis of the sulfonylamidyl amide and 3-imine indole derivatives with a wide range of substrates in the absence of any oxidants and additives.

A silver-catalyzed 2-isocyanobiaryls insertion/cyclization with phosphine oxides was described for the construction of the 6-phosphorylated phenanthridines through radical addition of in situ formed P-centered radical to 2-isocyanobiphenyls and homolytic aromatic substitution process. The reactions could proceed smoothly to give the desired 6-phosphorylated phenanthridines promoted by AgOAc (20 mol %) with PhI(OAc)2 (3.0 equiv).

A method for palladium-catalyzed cascade reactions of isocyanides with enaminones has been developed. This methodology provides a direct approach to 4-aminoquinoline derivatives under mild conditions with up to 98% yields.

A cobalt-catalyzed [4 + 1] cycloaddition of easily accessible amides with isocyanides for the efficient synthesis of 3-iminoisoindolinone derivatives in high yield under mild conditions via intramolecular C(sp

A series of HSO 4 − functionalized ILs was synthesized and used as efficient, green, and metal-free catalysts for benzylation. Notably, the catalytic system has wide substrate scopes and the ionic liquid catalysts were applied to investigate three different types of nucleophiles to give the desired benzylation products with moderate to excellent yields.

An efficient and practical synthesis of benzothiazine by K2S initiated sulfur insertion reaction with enaminones via electron catalysis is developed. This protocol provides a new, environment-friendly and simple strategy to construct benzothiazine derivatives via formation of two C–S bonds under transition metal-free, additive-free and oxidant-free conditions. K2S not only provides the sulfur insertion source, but also ignites the reaction through the formation of a trisulfur radical anion and electrons in DMF.

Palladium-catalyzed intramolecular Heck reaction and aminopalladation of N-(2-(1-phenylvinyl)phenyl)aniline for the efficient synthesis of dihydroindeno[1,2,3-kl]acridines and 3-arylindoles via tuning of the phosphine ligands and solvents under two optimized conditions are reported. The reaction follows a 1,4-Pd migration, aminopalladation, C(sp2)–H activation, as well as five- and six-membered-ring fusion to form different products. The dihydroindeno[1,2,3-kl]acridine derivatives showed higher triplet energy (ET) levels than common blue phosphorescent dopant and may serve as good host candidates for blue triplet emitters.

A chemoselective palladium-catalyzed isocyanide insertion reaction of enaminones was developed. Amide derivatives were synthesized by this C–H functionalization and subsequent hydrolysis reactions. 4-Aminoquinoline derivatives were prepared by this C–H functionalization, which includes a 1,3-palladium migration in the process.

A silver-catalyzed 2-isocyanobiaryls insertion/cyclization with phosphine oxides was described for the construction of the 6-phosphorylated phenanthridines through radical addition of in situ formed P-centered radical to 2-isocyanobiphenyls and homolytic aromatic substitution process. The reactions could proceed smoothly to give the desired 6-phosphorylated phenanthridines promoted by AgOAc (20 mol %) with PhI(OAc)2 (3.0 equiv).

An efficient method for the construction of 6-alkyl phenanthridines by tert-butyl peroxybenzoate (TBPB)-mediated 2-isocyanobiaryl insertion with 1,4-dioxane was established. Two new C–C bonds were formed in this reaction via a sequential C(sp3)–H/C(sp2)–H bond functionalization under metal-free conditions.

1-Pentyl-3-methylimidazolium hydrogen sulfate and several structurally related ionic liquids are synthesized and applied as catalyst for the benzylation of nitrogen, sulfur, and carbon nucleophiles.

An efficient method for the construction of 6-alkyl phenanthridines by tert-butyl peroxybenzoate (TBPB)-mediated 2-isocyanobiaryl insertion with 1,4-dioxane was established. Two new C-C bonds were formed in this reaction via a sequential C(sp(3))-H/C(sp(2))-H bond functionalization under metal-free conditions.