Iodine-mediated synthesis of sulfur-bridged enaminones and chromones via double C(sp<sup>2</sup>)–H thiolation
作者:Yong Gao、Li Wei、Yunyun Liu、Jie-Ping Wan
DOI:10.1039/c7ob00619e
日期:——
reactions of various enaminones with elemental sulfur giving rise to both sulfur-bridged enaminones and chromones have been realized via iodine promotion. All products were furnished by means of double C(sp2)–H bond thiolation without using any metal catalyst or sensitive oxidant, providing a simple and efficient protocol for the synthesis of diverse sulfur derivatives of enaminones.
Zn(OTf)<sub>2</sub>-Catalyzed Formal [3 + 3] Cascade Annulation of Propargylic Alcohols with 2-Aminochromones: Accessing the Chromeno[2,3-<i>b</i>]pyridines
作者:Pei Tong、Zhou Sun、Shutao Wang、Yuan Zhang、Ying Li
DOI:10.1021/acs.joc.9b02120
日期:2019.11.1
A Zn(OTf)2-catalyzed formal [3 + 3] cascade annulation strategy for the synthesis of functionalized chromeno[2,3-b]pyridines has been developed using propargylicalcohols and 2-aminochromones as the substrates. The protocol provides a convenient and atom-economical method of accessing a broad range of chromeno[2,3-b]pyridine derivatives in excellent yields with good functional-group tolerance. The
KIO<sub>3</sub>-Catalyzed Domino C(sp<sup>2</sup>)−H Bond Sulfenylation and C−N Bond Oxygenation of Enaminones toward the Synthesis of 3-Sulfenylated Chromones
作者:Shanshan Zhong、Yunyun Liu、Xiaoji Cao、Jie-Ping Wan
DOI:10.1002/cctc.201601273
日期:2017.2.6
With 2‐hydroxyphenyl‐functionalized enaminones and thiophenols as the starting materials, the facilesynthesis of 3‐sulfenylated chromones has been realized through a KIO3‐catalyzed domino reaction of C−H sulfenylation and subsequent C−N‐cleavage‐based C−O bondformation. The reaction was performed under transition‐metal‐free conditions in ethyl lactate, a bioavailable ecofriendly medium.
Synthesis of 3-halochromones with simple KX halogen sources enabled by <i>in situ</i> halide oxidation
作者:Yan Lin、Jie-Ping Wan、Yunyun Liu
DOI:10.1039/d0nj00825g
日期:——
On the basis of a designated in situ oxidation tactic, the synthesis of 3-halochromones has been realized for the first time by using simple KX (X = Br, I) salts as halogen sources. Instead of the free radical process, the control experiments indicate that the reported reactions proceed through a halogenium intermediate. Compared to the known synthetic methods relying on molecular halogen, haloid acid
An efficient synthesis of 4H-chromene-4-ones via enamino ketones, with cyclization by using T3P® under microwave heating is described. This is the first report for the synthesis of chromones by using T3P®. Significant features of this method include short reaction times and high-purity products.