RESUMEN
Under the catalysis of Rh2(OAc)4 (10 mol%) and binapbisphosphine ligand (±)-L3 (20 mol%) in DCE at 80 °C, the cascade cyclization of diazoimides with alkylidenepyrazolones underwent stereoselectively (dr > 20:1), affording pyrazole-fused oxa-bridged oxazocines in reasonable chemical yields. The chemical structure and relative configuration of title products were firmly identified by X-ray diffraction analysis.
RESUMEN
Under the catalysis of Pd(OAc)2/dppf/Na2CO3, the decarboxylative 1,4-addition reaction of benzofuran-based azadienes with allyl phenyl carbonates took place easily and delivered the desired products in reasonable chemical yields. The chemical structure of the target compounds was clearly identified by single crystal X-ray structural analysis.
RESUMEN
Under the catalysis of Pd2(dba)3·CHCl3/(±)-L5 in THF at room temperature, the three-component decarboxylative coupling reactions among alkylidene pyrazolones, allyl carbonates and active methylene compounds proceeded readily and furnished the desired products in acceptable chemical yields. The chemical architecture of the obtained products was unambiguously confirmed by single crystal X-ray analysis.
RESUMEN
Chirality, an intrinsic degree of freedom, has been barely exploited as the information carriers in data transmission, processing, computing, etc. Recently the magnons in antiferromagnets were proposed to carry both right-handed and left-handed chiralities, shedding a light on chirality-based spintronics in which chirality-based computing architectures and chiral magnonic devices may become feasible. However, the practical platform for chirality-based spintronics remains absent yet. Here we report an artificial ferrimagnetic Py/Gd/Py/Gd/Py/Pt multilayer by which the switching, reading, and modulation of magnon chirality are demonstrated. In particular, the coexisting resonance modes of ferromagnetic and antiferromagnetic characteristics permit the high adjustability and easy control of magnon chirality. As a main result, we unambiguously demonstrated that Py precessions with opposite chiralities pump spin currents of opposite spin polarizations into the Pt layer. Our result manifests the chirality as an independent degree of freedom and illustrates a practical magnonic platform for exploiting chirality, paving the way for chirality-based spintronics.
RESUMEN
Under the reaction conditions of Pd(PPh3)4 (2.5 mol %) and PPh3 (10 mol %) in EtOAc at 60 °C, the formal (5 + 6) cycloaddition of vinylethylene carbonates with isatoic anhydrides proceeded smoothly and furnished medium-sized N,O-containing heterocycles in reasonable chemical yields. The chemical structures of the title products were clearly identified by X-ray diffraction analysis.
RESUMEN
In the presence of the chiral Pd(0)/ligand complex, vinyl benzoxazinanones underwent the [4+2] cycloaddition with alkylidene pyrazolones smoothly and delivered spiropyrazolones in reasonable yields, diastereoselectivities, and eneantioselectivities (up to >99% yield, >99:1 dr and 99% ee). The absolute configuration of the obtained spiropyrazolones was unambiguously characterized with the use of X-ray single-crystal structure analysis. Moreover, the reaction mechanism was assumed to interpret the formation of the target compounds.
RESUMEN
Under the catalysis of Pd2(dba)3 (2.5 mol%), PPh3 (10.0 mol%) and TMSCl (1.0 eq.), the formal [5+2] cycloaddition of vinylethylene carbonates to oxazol-5-(4H)-ones proceeded readily in THF at 60 °C to r.t., thus furnishing 3,4-dihydrooxepin-2(7H)-ones in 67-99% chemical yields. The chemical structure of one compound was confirmed by X-ray diffraction analysis, and the others were suggested by inference.
RESUMEN
Under the catalysis of chiral palladium(0)/ligand complex, the [4 + 2] cycloaddition between vinyl benzoxazinanones and barbiturate-based olefins proceeded readily and provided barbiturate-fused spirotetrahydroquinolines in up to 96% chemical yield with up to >99:1 dr and 97% ee. The absolute configuration of barbiturate-fused spirotetrahydroquinolines was clearly identified by X-ray single crystal structure analysis. The reaction mechanism was proposed to shed light on the enantioselective formation of barbiturate-fused spirotetrahydroquinolines.
RESUMEN
In the presence of TMSCl, the [3 + 2] cycloaddition of oxazol-5-(4H)-ones with nitrones proceeded smoothly and furnished the desired isoxazolidin-5-ones with high diastereoselectivities in reasonable chemical yields. The chemical structure of the title compounds was firmly confirmed by X-ray single-crystal structure analysis.
RESUMEN
In the presence of CuI, 1,3-dipolar cycloadditions of N,N'-cyclic azomethine imines with iminooxindoles proceeded readily and furnished novel oxindole spiro-N,N-bicyclic heterocycles in moderate to excellent chemical yields with excellent diastereoselectivities.
RESUMEN
Under catalysis of 10 mol % of Et3N, the [3 + 2] cycloaddition of barbiturate-based olefins with 3-isothiocyanato oxindoles underwent smoothly and afforded the desired dispirobarbiturates in up to 99% yield with up to 99:1 dr. The relative configuration of the dispirobarbiturates was unambiguously determined by X-ray single-crystal structure analysis. The reaction mechanism was proposed to shed light on the diastereoselective formation of the dispirobarbiturates.