Oxidative Generation of Diarylcarbenium Ion Pools

Abstract

"Cation pools" of diarylcarbenium ions have been generated by the oxidative C-H bond dissociation of diarylmethanes using anodic oxidation. "Diarylcarbenium ion pools" thus generated react with various nucleophiles, such as allylsilanes, ketene silyl acetals, and aromatic compounds. The reductive homocoupling of the "diarylcarbenium ion pool" has been achieved. The dimer thus obtained also serves as a precursor of the "diarylcarbenium ion pool" via oxidative C-C bond dissociation. [reaction: see text]

Carbocations in Superacid Systems

“…Strong contribution from para-(and ortho-) quinonoidal resonance forms are responsible for much of the reactivity of the ion. 351 The accumulation of the cations was confirmed by 13 C NMR spectroscopy: A signal for the 4,4 0 -difluorobenzhydryl cation was detected at d 13 C 192.6, which is close to the value (d 13 C 193.3) observed in superacid medium (HSO 3 F-SbF 5 -SO 2 ClF). Reindl et al 346 used force field (MMP2) and ab initio (MP2/6-31G*) methods to show, however, that stabilization by the phenyl group is attenuated.…”

FeCl2‐Catalyzed Selective CC Bond Formation by Oxidative Activation of a Benzylic CH Bond

“…Alternatively, various catalytic methods have been developed recently that allow the direct functionalization of benzylic CH bonds (Scheme , path C) 3. 4…”

Synthetic Organic Electrochemical Methods Since 2000: On the Verge of a Renaissance

“…These cations may be trapped with carbon-centered nucleophiles such as heteroarenes, organozinc reagents, or silyl ketene acetals (Figure 17I). 288,289 Alternatively, they may be subjected to cathodic reduction where the ensuing radical was found to undergo homodimerization. Generation of the diarylcarbenium cation pool could be facilitated with silane electroaxuiliaries—this strategy also allowed the synthesis of dendritic molecules through iterative cation pool formation and nucleophile trapping (Figure 17J).…”