Enantioselective synthesis of α,α-diarylketones by sequential visible light photoactivation and phosphoric acid catalysis

Catalytic Asymmetric Construction of α,α-Diaryl Aldehydes via Oxo-Hydroarylation of Terminal Alkynes

Chiral aldehydes containing a tertiary stereogenic center are versatile building blocks in organic chemistry. In particular, such structural motifs bearing an α,α-diaryl moiety are very challenging scaffolds and their efficient asymmetric synthesis is not reported. In this work, a phosphoric acid-catalyzed enantioselective synthesis of α,α-diaryl aldehydes from simple terminal alkynes is presented. This approach yields a wide range of highly enolizable α,α-diaryl aldehydes in good yields with excellent enantioselectivities. Facile transformations of the products, as well as an efficient synthesis of bioactive molecules, including an effective anti-smallpox agent and an FDA-approved antidepressant drug (+)-sertraline, are demonstrated.

Palladium complex supported on the surface of magnetic Fe3O4 nanoparticles: an ecofriendly catalyst for carbonylative Suzuki-coupling reactions

Diaryl ketone derivatives include well-known compounds with important physiological and biological properties. In order to prepare diaryl ketone derivatives, we constructed a pallidum (0) complex immobilized on Fe3O4 nanoparticles modified with aminobenzoic acid and phenanthroline [Fe3O4@ABA/Phen-DCA-Pd(0)], and evaluated its catalytic performance for carbonylative Suzuki-coupling reactions of aryl iodides with aryl boronic acid in the presence of Mo(CO)6 as the CO source under mild conditions. FT-IR, SEM, TEM, EDX, VSM, TGA, XRD, ICP-OES and Elemental mapping techniques were employed to identify the structure of the Fe3O4@ABA/Phen-DCA-Pd(0) nanocatalyst. Different derivatives of aryl iodides and aryl boronic acids containing withdrawing and donating functional groups were studied for the preparation of diaryl ketones. Also, various derivatives of heteroaryl iodides and boronic acids were used and the desired products were prepared with high yields. The Fe3O4@ABA/Phen-DCA-Pd(0) nanocatalyst was separated magnetically and reused 7 consecutive times without reducing its catalytic activity. VSM, TEM and ICP-OES spectroscopic techniques confirmed that the synthesized Fe3O4@ABA/Phen-DCA-Pd(0) catalyst was still stable and maintained its structure despite repeated reuse.