Palladium-Catalyzed Aminomethylation of Nitrodienes and Dienones via Double C-N Bond Activation

Main observation and conclusion A new strategy for the generation of the active Pd-alkyl species from aminal via C-N bond activation has been established,in which the formation of zwitterionic intermediate through aza-Michael addition of aminal to nitrodienes or dienones is identified as a key step for the activation of the C-N bond.The efficient strategy has enabled a new palladium-catalyzed a-aminomethylation of nitro-dienes and dienones via double C-N bond activation.The scope and versatility of the reaction were demonstrated and a broad range of substrates bearing electron-donating and-withdrawing groups on the aromatic rings were all compatible with this reaction to furnish the desired a-aminomethylated products in moderate to good yields with excellent regioselectivities and E/Z selectivities.

Synthesis of 4-Desmethyl-Rippertenol and 7-Epi-Rippertenol via Photoinduced Cyclization of Dienones

The synthesis of cycloheptanoid-based fused polycyclic frameworks is a challenge for organic chemists due to unfavorable entropic factors and ring strains.Herein,a concise synthesis of 4-desmethyl-rippertenol and 7-epi-rippertenol bearing a unique,[6,6,5,7]-fused tetracyclic framework is reported.The route features a novel photoinduced intramolecular cyclization ofα-cyclopropyl dienone followed by an unexpected thermal 1,5-hydrogen migration.

Homogeneous and Heterogeneous Performances of Pyridinium Ionic Liquids in the Allylic Oxidation of Ionone-like Dienes

The combination of relatively low-cost ionic liquids, simple copper salt, and terminal oxidant tert-butyl hydroperoxide provided an efficient and environmentally friendly approach to the preparation of ionone-like dienones. Six pyridinium ionic liquids were evaluated in allylic oxidation of α-ionone and β-ionone. The 60%-70% yields of 3-oxo-α-ionone were obtained with 0.02 0.20 mmol of CuCl2·2H2O as catalyst, 3-5 mmol of tert-butyl hydroperoxide as oxidant and 1 g of [Bpy]PF6 as solvent for 4-20 h at 60℃. The facile recovery and recycle of catalyst were also achieved. More significantly, peculiar phase behaviors of [Bpy]PF6 and [Epy]PF6 offered the catalytic system advantages of homogeneous reaction and heterogeneous separation. Scanning electron microscope （SEM） images of [Bpy]PF6 provided evidences for the behaviors. Transmission electron microscope （TEM） micrographs showed copper salt nanoparticles catalyst formed and stabilized in pyridinium ionic liquids.

Dienone-phenol Rearrangement of C-9 Oxygenated Decalinic Dienone and Analogs through B-Ring Cleavage

Dehydrogenation of 9-hydroxy decalinic enones and analogs with DDQ resulted in a formal dienone-phenol type rearrangement via B-ring cleavage, while the corresponding dienone acetates underwent base-catalyzed formal dienone-phenol type rearrangement analogously.