- Substituent-Oriented Synthesis of Substituted Pyrazoles/Chromeno[3,2- c]pyrazoles via Sequential Reactions of Chromones/3-Chlorochromones and Tosylhydrazones
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A facile and efficient synthetic strategy for the chemoselective synthesis of monocyclic/tricyclic-fused pyrazoles was developed, and it was oriented by different 3-position substituents (H or Cl) on the chromones. The reaction proceeded in a one-pot sequential way with a broad substrate scope and moderate to excellent yields.
- Dai, Tianzi,Li, Qunyi,Zhang, Xiaofei,Yang, Chunhao
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p. 5913 - 5921
(2019/05/10)
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- Rhodium/chiral diene-catalyzed asymmetric 1,4-addition of arylboronic acids to chromones: A highly enantioselective pathway for accessing chiral flavanones
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Chromone has been noted to be one of the most challenging substrates in the asymmetric 1,4-addi-tion of α,β-unsaturated carbonyl compounds. By employing the rhodium complex associated with a chiral diene ligand, (R,R)-Ph-bod, the 1,4-addition of a variety of aryl-boronic acids was realized to give high yields of the corresponding flavanones with excellent enantioselectivities (≥97% ee, 99% ee for most substrates). Ring-opening side products, which would lead to erosion of product enantioselectivity, were not observed under the stated reaction conditions.
- He, Qijie,Wang, Jun,So, Chau Ming,Hayashi, Tamio,Bian, Zhaoxiang
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supporting information
p. 540 - 543
(2015/05/05)
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- 2,3-Unsubstituted chromones and their enaminone precursors as versatile reagents for the synthesis of fused pyridines
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A divergent and regioselective approach to fused pyridines was developed through formal [3 + 3] cyclocondensations from simple 2,3-unsubstituted chromones or their enaminone precursors.
- Iaroshenko, Viktor O.,Mkrtchyan, Satenik,Gevorgyan, Ashot,Miliutina, Mariia,Villinger, Alexander,Volochnyuk, Dmytro,Sosnovskikh, Vyacheslav Ya.,Langer, Peter
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supporting information; experimental part
p. 890 - 894
(2012/02/02)
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