Nucleophilic substitution at phosphorus. Phosphorothioates

Stepwise walden inversion in nucleophilic substitution at phosphorus.

We have studied the mechanism of S(N)2@P reactions in the model systems X(-) + PMe(2)Y and X(-) + POR(2)Y (with R=Me, OH, OMe; and X, Y=Cl, OH, MeO) using density functional theory at OLYP/TZ2P. Our main purpose is to analyze the nature of the Walden inversion in our model nucleophilic substitution reactions. Walden inversion is well-known to proceed, in general, as a concerted umbrella motion ...

Nucleophilic Substitution and Elimination

What does the term "nucleophilic substitution" imply? • A nucleophile is an the electron rich species that will react with an electron poor species • A substitution implies that one group replaces another. Nucleophilic substitution reactions occur when an electron rich species, the nucleophile, reacts at an electrophilic saturated C atom attached to an electronegative group (important), the lea...

Modern Nucleophilic Aromatic Substitution

Gas phase nucleophilic substitution

The literature on gas phase nucleophilic substitution reactions at aliphatic carbon has been reviewed. The emphasis has been on journal articles published in the period 1990–2001. The present review outlines our current understanding of concepts such as potential energy surfaces, structure–energy relationships, microsolvation, and dynamical and mechanistic details based on both experimental and...

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...