Similarities and Differences between Site-Selective Acylation and Phosphorylation of Amphiphilic Diols, Promoted by Nucleophilic Organocatalysts Decorated with Outer-Sphere Appendages

We demonstrated recently that organocatalysts, based on a nucleophilic core (N-alkylimidazole or 4-aminopyridine) and decorated with an extensive secondary-sphere envelope (connected to the through benzyl substituent), strongly affect site selectivity in acylation phosphorylation of amphiphilic diols, sometimes entirely overriding innate predisposition substrate. Preliminary studies pointed out that, despite some similarities, there are differences between two transformations, regarding influence various catalyst features selectivity. To fully elucidate this, extended families organocatalysts said design were examined, activity- selectivity-wise, abovementioned transformations model alcohol diol substrates. A comparison reactions revealed while inductive electron donation o,o-dialkoxybenzyl substituent core, combined catalytic intermediate-stabilizing components, causes increase activity both phosphorylation, its effect is opposite. On other hand, lipophilicity appendages improves apolar site-favoring reactions. Thus, factors work concert but opposite directions acylation.