2-Hydroxylation of 1,3-Diketones with Atmospheric Oxygen
摘要:
An efficient method for the 2-hydroxylation of 1,3-diketones by using atmospheric oxygen as an oxidant under transition-metal-free condition is described. The protocol has the advantages of using an inexpensive and stable oxidant, producing high yields, and requiring ecofriendly conditions.
2-Hydroxylation of 1,3-Diketones with Atmospheric Oxygen
摘要:
An efficient method for the 2-hydroxylation of 1,3-diketones by using atmospheric oxygen as an oxidant under transition-metal-free condition is described. The protocol has the advantages of using an inexpensive and stable oxidant, producing high yields, and requiring ecofriendly conditions.
Some new 3,5-diaryl-1H-pyrazoles were prepared from aryl methyl ketones via Claisen condensation with aromatic esters and followed by cyclization with hydrazine monohydrate. Their structures were confirmed by IR, 1H NMR spectroscopy, mass spectrometry and elemental analysis. The X-ray structure for 3(5)-(4-tert-butylphenyl)-5(3)-(4-methoxyphenyl)-1H-pyrazole (2b) was presented. The results show that
一些新的3,5-二芳基-1 H-吡唑是由芳基甲基酮经克莱森与芳香族酯缩合制备的,然后与一水合肼环化。通过IR,1 H NMR光谱,质谱和元素分析确认了它们的结构。给出了3(5)-(4-叔丁基苯基)-5(3)-(4-甲氧基苯基)-1H-吡唑(2b)的X射线结构。结果表明,化合物2b以互变异构体I和II存在,其分子通过N–H··N分子间氢键连接,形成由互变异构体I和II组成的环状二聚体。
Gold-Catalyzed Formal C−C Bond Insertion Reaction of 2-Aryl-2-diazoesters with 1,3-Diketones
作者:Yuan-Yuan Ren、Mo Chen、Ke Li、Shou-Fei Zhu
DOI:10.1002/asia.201800934
日期:2018.9.17
Brønsted acid to the reaction mixture improves the yield of the C−C bond insertion product. A reaction mechanism involving cyclopropanation of a gold carbenoid with an enolate and ring‐opening of the resulting donor–acceptor‐type cyclopropane intermediate is proposed. This mechanism differs from that of the traditional Lewis‐acid‐catalyzed C−C bond insertionreaction of diazo compounds with monocarbonyl
Five diaroylmethanatoboron difluoride derivatives were prepared from aryl methyl ketones via Claisen condensation with aromatic esters and followed by complexation with boron trifluoride etherate. Their structures and spectroscopic properties were studied by elemental analysis, IR, NMR, ESI–MS, UV and fluorescence spectroscopy. The results showed that these boron complexes had strong fluorescent peaks
2-Hydroxylation of 1,3-Diketones with Atmospheric Oxygen
作者:Zheng Li、Tianpeng Li、Jiasheng Li、Lili He、Xianggui Jia、Jingya Yang
DOI:10.1055/s-0035-1560647
日期:——
An efficient method for the 2-hydroxylation of 1,3-diketones by using atmospheric oxygen as an oxidant under transition-metal-free condition is described. The protocol has the advantages of using an inexpensive and stable oxidant, producing high yields, and requiring ecofriendly conditions.