Microwave-assisted sequential amide bond formation and intramolecular amidation: a rapid entry to functionalized oxindoles

Biaryl phosphane ligands in palladium-catalyzed amination

Palladium-catalyzed amination reactions of aryl halides have undergone rapid development in the last 12 years, largely driven by the implementation of new classes of ligands. Biaryl phosphanes have proven to provide especially active catalysts in this context. This Review discusses the application of these catalysts in C-N cross-coupling reactions in the synthesis of heterocycles and pharmaceuticals, in materials science, and in natural product synthesis.

Rapid access to oxindoles by the combined use of an Ugi four-component reaction and a microwave-assisted intramolecular Buchwald-Hartwig amidation reaction

A two-step sequence involving an Ugi four-component reaction (Ugi-4CR) and a palladium-catalyzed intramolecular amidation of aryl iodide has been developed for rapid access to functionalized oxindole (1). Microwave heating was used to accelerate and to improve the efficiency of the intramolecular Buchwald-Hartwig reaction.

A fluorous, Pummerer cyclative-capture strategy for the synthesis of N-heterocycles

A fluorous, cyclative-capture strategy based on a new Pummerer cyclization process allows rapid access to tagged, heterocyclic frameworks. Convenient modification of the fluorous, heterocyclic scaffolds by using a variety of approaches including Pd-catalyzed cross-couplings is possible. Traceless, reductive cleavage of the fluorous-phase tag or oxidative cleavage and further elaboration, completes a strategy for the high-throughput, fluorous-phase synthesis of a diverse range of N-heterocycles.

Expedited Palladium-Catalyzed Amination of Aryl Nonaflates through the Use of Microwave-Irradiation and Soluble Organic Amine Bases

[reaction: see text] Microwave-assisted, palladium-catalyzed C-N bond-forming reactions with aryl/heteroaryl nonaflates and amines using the soluble amine bases DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) or MTBD (7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene) and ligands (1-3) resulted in good to excellent yields (71-99%) of arylamines in short reaction times (1-45 min).

A Domino Amidation Route to Indolines and Indoles: Rapid Syntheses of Anhydrolycorinone, Hippadine, Oxoassoanine, and Pratosine

[reaction: see text] When subjected to palladium-catalyzed amidation conditions, 2-triflyloxy phenethyl carbonates undergo, in addition to the expected aryl cross-coupling, an additional amidation with net displacement of the carbonate. The result is a one-step synthesis of indolines which may be oxidized to indoles. The utility of the procedure is illustrated by the two- or three-step syntheses of anhydrolycorinone, hippadine, oxoassoanine, and pratosine.