One Heck of a reaction : Treatment of arylboronic acids or aryltrifluoroborates with vinyl acetate by using a palladium(II) catalyst gives the corresponding styrenes (see scheme). No palladium reoxidant is needed and the vinylation is performed under non‐inert conditions
The first PdII‐catalyzed P arylation has been performed by using palladium acetate, the rigid bidentate ligand dmphen (dmphen=2,9‐dimethyl‐1,10‐phenanthroline), and without the addition of base or acid. Couplings of arylboronic acids or aryl trifluoroborates with H‐phosphonate dialkyl esters were conducted in 30 min with controlled microwave (MW) heating under non‐inert conditions. Aryl phosphites were also synthesized at room temperature with atmospheric air as the sole reoxidant. The arylated phosphonates were isolated in 44–90 % yields. The excellent chemoselectivity of the method was illustrated in the synthesis of a Mycobacterium tuberculosis glutamine synthetase (MTB‐GS) inhibitor. Online ESIMS was used to detect cationic palladium species in ongoing reactions directly, and a catalytic cycle has been proposed based on these results. 相似文献
The discovery of the first ligand-supported Pd(ii) catalysed oxidative Heck reaction with molecular oxygen as reoxidant and the scope with diverse arylboronic acids and olefins using only 1-2% of catalyst are reported. 相似文献
[reaction: see text] Synthesis of aryl triflates from phenols using N-phenyltriflimide requires only 6 min for completion when conducted with controlled microwave heating. The methodology was applied to both solution- and solid-phase conditions. Ten different aryl triflates were synthesized and isolated in good yields. Applications in high-throughput chemistry are suggested. 相似文献
Monoprotected 3-hydroxyindan-1-ones have been prepared in moderate to good yields by a new tandem reaction involving salicylaldehyde triflates and commercially available 2-hydroxyethyl vinyl ether. This one-pot annulation reaction proceeds in the presence of a palladium bidentate catalyst and results in the formation of two new ring systems. 相似文献
A fast and acid-free one-pot 0.2-30 mmol microwave methodology for direct ionic liquid-mediated preparation of lactams from lactones and primary amines has been developed. The protocol was investigated with a wide range of primary amines and a handful of lactones, including substrates with acid-sensitive substituents. Both gamma-lactams and delta-lactams were, despite the complete absence of a Br?nsted acid, obtained in useful to excellent yields after only 35 min of microwave processing. 相似文献