An efficient protocol for the amination of 6-chloropurine derivatives through nucleophilic aromatic substitution under microwave irradiation was developed and applied to the synthesis in two steps of a series of new acyclic nucleosides (acyclovir analogues) starting from commercially available compounds.

We present nucleophilic aromatic substitution of unsubstituted aryl chlorides via a mechanism that is catalytic in [CpRu(p-cymene)]PF6 and involves a Ru(η(6)-arylchloride) intermediate. From the spectroscopic evidence we infer that arene exchange is the rate limiting step in this process and develop several new Ru(ii) complexes that lower the activation barrier to arene exchange.

With a miniaturized (3 microL volume) fiber-optics based system for on-line measurement by UV/Vis spectroscopy, the reaction rate constants (at different pressures) and the activation volumes (deltaV(not =)) were determined for a nucleophilic aromatic substitution and an aza Diels-Alder reaction in a capillary microreactor.

An efficient solvent free reaction of 1-chloro-2-nitrobenzene with anilines to give N-substituted nitro anilines by nucleophilic aromatic substitution in good to excellent yields has been described. The effect of different salts on the reaction has also been studied.

The first total synthesis of pterocellin A (1) was achieved in 10 linear steps from commercially available kojic acid (6) and 2-bromo-3-pyridinol (11) in a convergent sequence. The key constructive steps are a directed lithiation to couple two pyridines and an intramolecular nucleophilic aromatic substitution to form 1. [structure: see text]

Several specific synthetic protocols were developed for the preparation from cyanuric chloride of a range of symmetric and non-symmetric di- and tri-substituted 1,3,5-triazines containing alkyl, aromatic, hindered, chiral and achiral hydroxyalkyl, ester and imidazole groups via sequential nucleophilic substitution of the C-Cl bond by C-O, C-N and C-S bonds.

Substitution effects are probed for novel N-heterocyclic stannylenes (NHSns), including 1,4-di(R)-tetrazole-5-stannylenes (1R), and 1,3-di(R)-tetrazole-5-stannylenes (2R), using B3LYP/6-311++G** level of theory. Nucleophilicity, multiplicity, and stability of 1R and 2R are calculated; with R = H, methyl, ethyl, i-propyl, t-butyl, Ph, OH, methoxy, NO2, CN and CF3. Asymmetric 2H appears more nucl...