Nucleophilic Aromatic Substitution (S N Ar) and Related Reactions of Porphyrinoids: Mechanistic and Regiochemical Aspects

Modern Nucleophilic Aromatic Substitution

Symmetry Analysis in Mechanistic Studies of Nucleophilic Substitution and β-Elimination Reactions

A mechanistic study of the bimolecular nucleophilic substitution (SN2) reaction for halomethane CH3X (X = Cl, Br, or I) is approached by using symmetry principles and molecular orbital theory. The electrophilicity of the functionalized sp–carbon is attributable to a 2p-orbital-based antibonding MO along the C–X bond. This antibonding MO, upon accepting an electron pair from a nucleophile, gives...

Nucleophilic aromatic substitution reactions of chloroazines with bisulfide (HS-) and polysulfides (Sn2-).

Reactions of bisulfide and polysulfides with chloroazines (important constituents of agrochemicals and textile dyes) were examined in aqueous solution at 25 degrees C. For atrazine, rates are first-order in polysulfide concentration, and polysulfide dianions are the principal reactive nucleophiles; no measurable reaction occurs with HS-. Second-order rate constants for reactions of an array of ...

Microwave-assisted N-Arylation of Indoles via C(sp2)–N(sp2) Bond Formation by Aromatic Nucleophilic Substitution Reactions

The N-arylindole subunit is an important species in many biologically active and pharmaceutically important compounds, which display antiestrogen [1], analgesic [2], antiallergy [3], antimicrobial [4], and neuroleptic activity [5]. Although the traditional coppercatalyzed coupling of an aryl halide with a heteroatombased nucleophile, the Ullmann-type coupling reaction, has remained a standard m...

Nucleophilic substitution reactions of pyranose polytosylates.

The 2,3,4-tri-toluenesulfonate ester derivatives of the methyl pyranosides of l-arabinose, d-ribose, d-lyxose, and d-xylose have been prepared, and their substitution reactions with various nucleophiles have been examined. For arabinose, xylose, and ribose, highly regioselective monosubstitutions were observed with benzoate, nitrite, and azide anions. These reactions have led to short and simpl...