Phenyl cation: A versatile intermediate

作者：Dichiarante Valentina; Protti Stefano; Fagnoni Maurizio^*

来源：Journal of Photochemistry and Photobiology A: Chemistry , 2017, 339: 103-113.

DOI：10.1016/j.jphotochem.2017.02.007

• Phenyl cations
• Diradicals
• Metal-free arylations
• Photoheterolysis
• Photoacid generators (PAGs)

Phenyl cations are short-lived electrophiles and can be smoothly generated by photolysis of aromatic halides (chlorides, fluorides) and esters (sulfonates, sulfates and phosphates) in protic media. Indeed, the heterolytic cleavage of an Aryl-LG bond (LG = leaving group; X, OR) allows for the generation of a triplet aryl cation (Ar-3(+)) that chemoselectively reacts with pi-bond nucleophiles to perform transition metal free arylations. Aryl cations can be also exploited in the generation of other high energy intermediates, such as diradicals (including ortho-arynes and alpha,n-didehydrotoluenes), potentially useful for medicinal applications. Since the generation of phenyl cations is always accompanied by the release of a strong acid (e.g. sulfonic acids), the phenyl cation precursors are actually non ionic photoacid generators (PAGs) that find useful applications in nanolithography.

• 出版日期2017-4-15