Studies on selective preparation of aromatic compounds. 20. Selective preparation of 2-mono- and 2,2'-disubstituted biphenyl using the tert-butyl group as a positional protective group
A metal-free protocol of direct C(sp3)–H cyanation with cyanobenziodoxolones functioning as both cyanating reagents and oxidants was developed. Unactivated substrates, such as alkanes, ethers and tertiary amines, were thereby transformed to the corresponding nitriles in moderate to high yields. Mechanistic studies indicated that the cyanation proceeded with two potential pathways, which is highly dependent
Metal-Free, Oxidant-Free, and Controllable Graphene Oxide Catalyzed Direct Iodination of Arenes and Ketones
作者:Jingyu Zhang、Shiguang Li、Guo-Jun Deng、Hang Gong
DOI:10.1002/cctc.201701182
日期:2018.1.23
oxide (GO)‐catalyzed iodination of arenes and ketones with iodine in a neutralmedium was explored. This iodination protocol was performed by using a simple technique to avoid the use of external metal catalysts and oxidants and harsh acidic/basic reaction conditions. In addition, by this method the degree of iodination could be controlled, and the reaction was scalable and compatible with air. This strategy
Rapid aerobic iodination of arenes mediated by hypervalent iodine in fluorinated solvents
作者:Jernej Iskra、S. Shaun Murphree
DOI:10.1016/j.tetlet.2017.01.003
日期:2017.2
Arenes are rapidly converted to the corresponding iodides by aerobic oxidative iodination at room temperature by treatment with iodine and catalytic quantities of nitrous acid in a fluorinated solvent. Dichloroiodic acid is proposed as the actual iodination reagent.
Revisiting the Urech Synthesis of Hydantoins: Direct Access to Enantiopure 1,5-Substituted Hydantoins Using Cyanobenziodoxolone
作者:Nina Declas、Franck Le Vaillant、Jerome Waser
DOI:10.1021/acs.orglett.8b03843
日期:2019.1.18
synthesis of enantiopure 1,5-substituted hydantoins was developed using a hypervalent iodine cyanation reagent (cyanobenziodoxolone, CBX) as a source of electrophilic carbon. Starting from inexpensive commercially available enantiopure protected amino acids, the method allowed the synthesis of various hydantoins without epimerization. Formation of hydantoins from dipeptides was also possible, but partial
Aerobic oxidative iodination of organic molecules activated by sodium nitrite
作者:Jernej Iskra、Stojan Stavber、Marko Zupan
DOI:10.1016/j.tetlet.2007.11.167
日期:2008.1
Aerobic oxidative iodination activated by sodium nitrite occurs effectively and selectively with 100% iodine atom economy with air as the oxidant. Silica-supported sulfuric acid was used for the activation of the catalyst and iodination. Thus, I2/NaNO2/air/silica-supported H2SO4 in acetonitrile iodinated aromatics, ketones and aldehydes effectively at ambient temperature.
亚硝酸钠活化的好氧氧化碘有效地,选择性地发生,以100%的碘原子经济性,以空气为氧化剂。二氧化硅负载的硫酸用于催化剂的活化和碘化。因此,在环境温度下,I 2 / NaNO 2 /空气/二氧化硅负载的H 2 SO 4在乙腈碘化的芳族化合物,酮和醛中有效。