Kumada-Tamao-Corriu Type Reaction of Aromatic Bromo- and Iodoamines with Grignard Reagents.

The first example of the Kumada-Tamao-Corriu type reaction of unprotected bromoanilines with Grignard reagents is described. The method uses a palladium source and a newly designed Buchwald-type ligand as the catalytic system. Secondary and tertiary bromo- and iodoamines were also successfully coupled to alkyl Grignard reagents. The products of the competitive ß-hydride elimination reaction were successfully reduced using a highly efficient electron-deficient phosphine ligand (BPhos). Mechanistic considerations allowed us to establish that the less electron-rich phosphine ligands stabilize the transition state much better than the electron-rich ones; hence, they increase the reaction yield and reduce the amount of ß-hydride elimination products. The developed method proved to be tolerant of many functional groups and can be applied to many different aromatic bromo- and iodoamines. Multigram synthesis of p-toluidine from 4-bromoaniline was achieved with a palladium catalyst loading of only 0.03 mol%.

Buchwald-Hartwig Amination of Aryl Halides with Heterocyclic Amines in the Synthesis of Highly Fluorescent Benzodifuran-Based Star-Shaped Organic Semiconductors.

The study of palladium-catalyzed amination of bromobenzene with aromatic and heterocyclic amines, widely used in the synthesis of organic semiconductors, was performed. The best conditions for the coupling of aryl bromides with carbazole, diphenylamine, phenoxazine, phenothiazine, 9,9-dimethyl-9,10-dihydroacridine, and their derivatives have been developed. Based on the results, nine new star-shaped organic semiconductors, exhibiting up to 100% fluorescent quantum yield in the 400-550 nm range, have been synthesized in good yields. The TDDFT calculations of the absorption spectra revealed a good correlation with experimental results and slight solvatochromic effects with a change in the polarity of the solvent.