Bronsted Acid-Catalyzed Regioselective Carboxamidation of 2-Indolylmethanols with Isonitriles

A regioselective direct carboxamidation reaction of 2-indolylmethanols with readily available isocyanoesters/isocyanides has been reported in this work. The reaction was catalyzed by Bronsted acid such as p-TsOH to deliver the benzylic regioselective amides in 67-86% yield under mild conditions. The developed methodology provides alternative access to traditional metal-free carboxamidation via C-C and C-O bond formation with high atom economy. Furthermore, the developed approach was diversified to synthesize chiral indole-2-carboxamide derivatives with a moderate enantiomeric excess (61-73% ee) using an (R)-chiral phosphoric acid.

Lewis Acid Mediated Conjugate Addition of Isocyanides to β-Hydroxy-α-diazo Carbonyls: Synthesis of β-Carboxamido-α-diazo Carbonyl Compounds

A Lewis acid mediated conjugate addition of isocyanides to β-hydroxy-α-diazo carbonyls has been developed for the first time. The reaction realizes the efficient construction of quaternary carbon centers and provides a novel and efficient strategy for the synthesis of β-carboxamido-α-diazo carbonyls that would be otherwise difficult to form in a single step. Further applications, including synthesis of methylenecyclohexane, spiro-β-lactam, and nitrogen-bridged tricyclic β-lactam, demonstrated the tremendous potential of the coupling reaction.

Catalytic synthesis of functionalized amidines via cobalt-carbene radical coupling with isocyanides and amines

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.

Transition Metal and Inner Transition Metal Catalyzed Amide Derivatives Formation through Isocyanide Chemistry

The synthesis of amides is a substantial research area in organic chemistry because of their ubiquitous presence in natural products and bioactive molecules. The use of easily accessible isocyanides as amidoyl (carbamoyl) synthons in cross-coupling reactions using transition metal and inner transition metöal catalysts is a current trend in this area. Isocyanides, owing to their coordination ability as a ligand and inherent electronic properties for reactions with various partners, have expanded the potential application of these transformations for the preparation of novel synthetic molecules and pharmaceutical candidates. This review gives an overview of the achievements in isocyanide-based transition metal and inner transition metal catalyzed amide formation and discusses highlights of the proposed distinct mechanisms.

1 Introduction

2 Synthesis of Arenecarboxamides

3 Synthesis of Alkanamides

4 Synthesis of Cyclic Amides

5 Formation of Alkynamides

6 Formation of Acrylamide-like Molecules

7 Formation of Ureas and Carbamates

8 Conclusion

Synthesis of unsymmetrical urea derivatives via one-pot sequential three-component reactions of cyclic 2-diazo-1,3-diketones, carbodiimides, and 1,2-dihaloethanes

An effective and operationally simple one-pot strategy has been developed for the synthesis of unsymmetrical urea derivatives via sequential three-component reactions of cyclic 2-dizao-1,3-diketones with carbodiimides and 1,2-dihaloethane.

Zn(OAc)2-catalyzed tandem cyclization of isocyanides, α-diazoketones, and anhydrides: a general route to polysubstituted maleimides

A zinc-catalyzed three-component reaction of isocyanides, α-diazoketones, and anhydrides has been realized as a novel and efficient method for the synthesis of polysubstituted maleimides.

A rhodium-catalyzed three-component reaction of arylisocyanides, trifluorodiazoethane, and activated methylene isocyanides or azomethine ylides: an efficient synthesis of trifluoroethyl-substituted imidazoles

A novel method for the synthesis of trifluoroethyl-substituted imidazoles is reported via a rhodium-catalyzed three-component reaction of isocyanides, 2,2,2-trifluorodiazoethane and activated methylene isocyanides or azomethine ylides.

Substituent-oriented C–N bond formation via N–H insertion or Wolff rearrangement of 5-aryl-1H-pyrazoles and diazo compounds

Substituent-oriented C–N bond formation of 5-aryl-1H-pyrazoles with diazo compounds.

Molecular iodine-mediated synthesis of thiocarbamates from thiols, isocyanides and water under metal-free conditions

A simple and practical molecular iodine-mediated method for the efficient construction of thiocarbamates from isocyanides, thiols and water under metal-free and mild conditions has been developed. A variety of thiocarbamates were easily synthesized through this methodology, which has the advantages of simple operation, eco-friendly conditions, good functional group tolerance, and readily accessible raw materials.

Divergent synthesis of 3,4-dihydrodibenzo[b,d]furan-1(2H)-ones and isocoumarins via additive-controlled chemoselective C–C or C–N bond cleavage

Rh(iii)-Catalyzed C–C/C–O bond formation between cyclic 2-diazo-1,3-diketones and salicylamides with additive-controlled chemoselectivity.

Rh(III)-Catalyzed C-H Activation/Intramolecular Cyclization: Access to N-Acyl-2,3-dihydro-1H-carbazol-4(9H)-ones from Cyclic 2-Diazo-1,3-diketones and N-Arylamides

A Rh(III)-catalyzed C-H activation/cyclization cascade reaction is described. The reaction involves cyclic 2-diazo-1,3-diketones and N-arylamides, and it proceeds via an intermolecular C-C bond formation and subsequent intramolecular C-N bond formation. A variety of N-acyl-2,3-dihydro-1H-carbazol-4(9H)-ones were obtained under mild conditions in good to excellent yields (65-90%). Key features of this strategy include high-efficiency, operational simplicity, scalability, and broad functional-group tolerance. In addition, H2O and N2 are the only byproducts. Carbazole derivatives with free NH groups can be easily obtained through N-deprotection reactions.