Ligand-Enabled Sequential C(sp³)–H and C(sp²)–H Diolefination Reaction via Palladium Catalyst

Abstract

Palladium-catalyzed sequential C­(sp3)–H and C­(sp2)–H bond diolefination reaction of o-toluidine has been realized for the first time using acetyl-protected aminoethyl phenyl thioether ligands. This novel reaction allows for preparation of the conjugated diene structure via an immediate second olefination on the basis of the first C­(sp3)–H olefination in one pot. Various triflyl-protected anilines and acrylates were used as coupling partners elegantly. Furthermore, the unpurified diolefination products can be easily converted to tetrahydroquinoline derivatives.

Carrier Transport in Low‐Dimensional Tin Perovskite Solar Cells

“…[ 36,83 ] Meanwhile, there are stronger exciton effects and electron–phonon couplings in the 2D Sn‐based films, and the introduction of bulky A sites results in stronger spin–orbit coupling and Rashba splitting when compared to the 3D perovskites. [ 84 ] Therefore, effective observation of carrier behavior in the low‐dimensional films becomes more important, in which a variety of spectroscopic analysis techniques are resorted. At present, the main spectroscopic analysis techniques used in low‐dimensional Sn‐based films include transient fluorescence spectra, time‐resolved fluorescence spectra, and femtosecond TAS.…”

Palladium-Catalyzed (3 + 2) Annulation of Aromatic Acids by C(sp3)–H Olefination and Decarboxylative Cross-Coupling Reaction

“…Nitrogen-containing heterocycles are common functional motifs in many pharmaceutical, agrochemical, and natural products . In particular, maleimides are important motifs found in many biologically active compounds .…”

Palladium-Catalyzed Tandem Diolefination Reaction of Benzaldehyde Enabled by a Remote Directing Group

“…Different strategies have also been developed in the past decade to achieve a diolefination reaction using transient metal (Scheme B), but the above diolefination reactions usually occurred on different sites of the substrates and were not tandem reactions. Last year, our group described a palladium-catalyzed sequential C­(sp 3 )–H and C­(sp 2 )–H bond diolefination reaction of o -toluidine (Scheme C) . This reaction allows for preparation of the conjugated diene structure via an immediate second olefination on the basis of the first C­(sp 3 )–H olefination in one pot.…”

“…Last year, our group described a palladium-catalyzed sequential C(sp 3 )−H and C(sp 2 )−H bond diolefination reaction of o-toluidine (Scheme 1C). 14 This reaction allows for preparation of the conjugated diene structure via an immediate second olefination on the basis of the first C(sp 3 )− H olefination in one pot. Based on the previous work in the activation reaction of benzaldehydes and our C−H diolefination reaction, we envisioned that a suitable directing group could lubricate the C−H diolefination reaction of benzaldehydes.…”