Rh(III)-Catalyzed [3 + 3] Annulation Reaction of Cyclopropenones and Sulfoxonium Ylides toward Trisubstituted 2-Pyrones
作者:Peng Zhou、Wei-Tao Yang、Anis Ur Rahman、Guigen Li、Bo Jiang
DOI:10.1021/acs.joc.9b02253
日期:2020.1.17
A new Rh(III)-catalyzed [3 + 3] annulation reaction between cyclopropenones and β-ketosulfoxonium ylides has been reported, enabling metal carbene insertion to access a wide range of trisubstituted 2-pyrones with moderate to excellent yields via C-C single-bond cleavage, in which sulfoxonium ylides serve as potential safe precursors of metal carbenes. This reaction occurred under redox-neutral conditions
Novel fluorescent 3,6-diaryl-4-phenyl-2-pyridone derivatives were synthesized and their fluorescent properties were investigated. These compounds emit intense brilliant blue fluorescence only in the solid state, not in solution. An electron-donating substituent on the 6-phenyl group caused a red-shift in fluorescence maxima.
Catalytic [3+3] Annulation of
<scp>β‐Ketoethers</scp>
and Cyclopropenones
<i>via</i>
C(sp
<sup>3</sup>
)—O/C—C Bond Cleavage under
<scp>Transition‐Metal</scp>
Free Conditions
carbon-oxygen (C—O) bond is highly important for the transformation of oxygen-rich biomass and industry chemicals. Herein, an efficient [3+3] annulation of β-ketoethers with cyclopropenones in the presence of catalytic base has been developed, which proceeds through the C(sp3)—O bonds cleavage in β-ketoethers and C—C bond cleavage in cyclopropenones under transition-metal free conditions. The cleavage of C(sp3)—O
Unusual Fluorescent Properties of 3,4,6-Triphenyl-α-pyrones
作者:Keisuke Hirano、Satoshi Minakata、Mitsuo Komatsu
DOI:10.1246/cl.2001.8
日期:2001.1
Novel fluorophores, 3,4,6-triphenyl-α-pyrone derivatives, were synthesized and their spectroscopic properties have been investigated. In the solid state they show intense greenish-yellow fluorescence, but not in solution. It is concluded that the 6-phenyl group is fixed at an angle of about 26° to the pyrone plane in the solid state by molecular packing and this fixation is required for this unique fluorescent property.