Iridium(III)-Catalyzed Intermolecular C(sp )-H Amidation for the Synthesis of Chiral 1,2-Diamines.

Chiral 1,2-diamines are privileged scaffolds among bioactive natural products, active pharmaceutical ingredients, ligands for transition-metal-based asymmetric catalysis and organocatalysts. Despite this interest, the construction of chiral 1,2-diamine motifs still remains a challenge. To address this, an iridium(III)-catalyzed intermolecular C(sp )-H amidation reaction was developed.

A General Enantioselective C-H Arylation Using an Immobilized Recoverable Palladium Catalyst.

We herein report a general and efficient enantioselective C-H arylation of aryl bromides based on the use of BozPhos as the bisphosphine ligand and SP-NHC-Pd as recoverable heterogeneous catalyst. By exploiting the "release and catch" mechanism of action of the catalytic system, we used BozPhos as a broadly applicable chiral ligand, furnishing high enantioselectivities across all types of examined substrates containing methyl, cyclopropyl and aryl C-H bonds. For each reaction, the reaction scope was investigated, giving rise to 30 enantioenriched products, obtained with high yields and enantioselectivities, and minimal palladium leaching.

C(sp )-H Arylation Promoted by a Heterogeneous Palladium-N-Heterocyclic Carbene Complex in Batch and Continuous Flow.

A heterogeneous reusable palladium(II)-bis(N-heterocyclic carbene) catalyst was prepared and shown to catalyze the intramolecular C(sp )-H activation/cyclization of N-alkyl-2-bromoanilines furnishing indolines. This new catalytic system was based on a bis-imidazolium ligand immobilized on a spaced cross-linked polystyrene support. The iodide ligands on the catalyst played a central role in the efficiency of the process occurring through a "release and catch" mechanism.