AROMATIC SUBSTITUTION WITH ARENESULFONYLOXY FREE RADICAL

Barton esters for initiator-free radical cyclisation with heteroaromatic substitution.

S-(1-Oxido-2-pyridinyl)-1,1,3,3-tetramethylthiouronium hexafluorophosphate (HOTT) facilitates the first examples of efficient radical cyclisation with (hetero)aromatic substitution via Barton ester intermediates. Cyclopropyl and alkyl radicals allow access to five, six and seven-membered alicyclic-ring fused heterocycles with and without an additional fused cyclopropane, including the skeleton ...

Modern Nucleophilic Aromatic Substitution

AROMATIZATION OF 1,4-DIHYDROPYRIDINES WITH FREE RADICAL REAGENTS

Oxidation of different types of 1,4-dihydropyridines with diphenylpicrylhydrazyl (DPP) and benzoyl peroxide (Bz2O2) as free radical oxidizing agents to pyridine derivatives is reported and a mechanism for this oxidation is also proposed.

Quantum Chemical Studies of Aromatic Substitution Reactions

In this thesis, density functional theory (DFT) is used to investigate the mechanisms and reactivities of electrophilic and nucleophilic aromatic substitution reactions (SEAr and SNAr respectively). For SEAr, the σ-complex intermediate is preceded by one (halogenation) or two (nitration) π-complex intermediates. Whereas the rate-determining transition state (TS) for nitration resembles the seco...

Polycyclic aromatic triptycenes: oxygen substitution cyclization strategies.

The cyclization and planarization of polycyclic aromatic hydrocarbons with concomitant oxygen substitution was achieved through acid catalyzed transetherification and oxygen-radical reactions. The triptycene scaffold enforces proximity of the alcohol and arene reacting partners and confers significant rigidity to the resulting π-system, expanding the tool set of iptycenes for materials applicat...