Pd-Catalyzed Indole Synthesis via C-H Activation and Bisamination Sequence with Diaziridinone

Pd-catalyzed efficient synthesis of 3-formylindole derivatives with diaziridinone

This work describes an efficient Pd-catalyzed annulation process of acetal alkynes, aryl iodides, and di-t-butyldiaziridinone to afford a variety of 3-formylindoles and their derivatives. The reaction likely proceeds through a regioselective Heck reaction followed by aryl C-H activation to form a pallada(II)cycle, which is bisaminated with diaziridinone via a pallada(IV)cycle. The utility of the current reaction process is demonstrated by the facile synthesis of bioactive indoles.

Pd-Catalyzed Regioselective Tandem Heck/C-H Activation/Bisamination Reactions with Ynamides and Diaziridinone. Rapid Access to 3-Aminoindoles

This work describes a highly efficient Pd-catalyzed annulation process of aryl iodides, ynamides, and di-tert-butyldiaziridinone. A wide variety of 3-aminoindoles bearing various functional groups have been readily obtained in up to 99% yield. 3-Aminoindole functionalities can also be easily introduced into medicinally important molecules. The reaction likely proceeds through a sequential regioselective Heck reaction and aryl C-H activation to form a pallada(II)cycle species, which is bisaminated with diaziridinone via a pallada(IV)cycle intermediate. The resulting 3-aminoindoles can serve as versatile precursors for the construction of structurally diverse aza-polycyclic compounds.

Palladium(0)-Catalyzed Regioselective Three-Component Cross-Coupling via C-H Activation: Synthesis of Eight-Membered Azacycles

A Pd(0)-catalyzed three-component cross-coupling reaction involving o-bromobenzylamines, aryl iodides, and alkynes was developed through C-H activation. This reaction exhibits excellent regioselectivity, selectively forming a C(vinyl)-C(aryl) bond. The process yields eight-membered azacycles as the products, providing straightforward access to such compounds using simple substrates.

Palladium-catalyzed domino cyclization and C-H amination of 1,7-enynes toward N-containing fused quinolin-2(1H)-ones

A palladium-catalyzed domino radical cyclization and C-H amination of 1,7-enynes has been developed for the rapid establishment of N-containing fused quinolin-2(1H)-one scaffolds. The reaction of 1,7-enynes with perfluoroalkyl iodides and di-t-butyldiaziridinone worked well to give a wide range of N-containing fused quinolin-2(1H)-one derivatives in high yields. Notably, this method could be used in the late-stage modifications of various drugs.

Pd-Catalyzed Aryl C-H Amination with Diaziridinone

This work describes an efficient Pd-catalyzed ortho-C-H amination of N-(quinolin-8-yl)benzamides with di-t-butyldiaziridinone, providing a variety of anthranilic amides in good yields. The reaction likely involves the formation of a pallada(II)heterocycle via aryl C-H activation and subsequent amination with di-t-butyldiaziridinone.

Synthesis of Indoles via Domino Reactions of 2-Methoxytoluene and Nitriles

2-Arylindoles are privileged structures widely present in biologically active molecules. New sustainable synthetic routes toward their synthesis are, therefore, in high demand. Herein, a mixed base-promoted benzylic C-H deprotonation of commercially available ortho-anisoles, addition of the resulting anion to benzonitriles, and S_NAr to displace the methoxy group provide indoles. A diverse array of 2-arylindoles is prepared with good yields (>30 examples, yields up to 99%) without added transition metal catalysts.

Photoredox/Iron Dual-Catalyzed Insertion of Acyl Nitrenes into C-H Bonds

In this work, the use of N-acyloxybenzamides as efficient acyl nitrene precursors under photoredox/iron dual catalysis is reported. The resulting acyl nitrenes could be captured by various types of C-H bonds and S- or P-containing molecules. Mechanism investigations suggested that the formation of the acyl nitrene from the N-acyloxybenzamide occurs by a photoredox process, and it is believed that in this redox process oxidative N-H bond cleavage of the N-acyloxybenzamide occurs prior to reductive N-O bond cleavage of the N-acyloxybenzamide.