《Metal-free synthesis of 3-chalcogenyl chromones from alkynyl aryl ketones and diorganyl diselenides/disulfides mediated by PIFA》 was published in Organic Chemistry Frontiers in 2020. These research results belong to Ai, Zhenkang; Xiao, Jiaxi; Li, Yadong; Guo, Boying; Du, Yunfei; Zhao, Kang. Reference of 1,2-Diphenyldisulfane The article mentions the following:
The 3-selenyl/sulfenyl chromones/thiochromones I (R = Ph, Me, 4-chlorophenyl, etc.; R1 = H, 7-Me, 6-Cl, 5-CF3, etc.; R2 = Ph, cyclopropyl, thiophen-3-yl, etc.) were conveniently synthesized from the PIFA-mediated reactions between alkynyl aryl ketones bearing an ortho-methoxy/methylthio group R1-2-XMe-C6H3C(O)CCR2 and diorganyl diselenides/disulfides RYYR (Y = Se/S). This metal-free approach is postulated to first undergo the formation of the reactive RSeOCOCF3 or RSOCOCF3 from the reaction of diorganyl diselenides or disulfides with PIFA, followed by the electrophilic cyclization of alkynyl aryl ketones enabled by the electrophilic species generated herein. In the part of experimental materials, we found many familiar compounds, such as 1,2-Diphenyldisulfane(cas: 882-33-7Reference of 1,2-Diphenyldisulfane)
1,2-Diphenyldisulfane(cas: 882-33-7) belongs to ethers.Oxygen is more electronegative than carbon, thus the alpha hydrogens of ethers are more acidic than those of simple hydrocarbons. Reference of 1,2-Diphenyldisulfane They are far less acidic than alpha hydrogens of carbonyl groups (such as in ketones or aldehydes), however.
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem