Annelated Pyridine Bases for the Selective Acylation of 1,2-Diols

A set of 24 annelated derivatives of 4-diaminopyridine (DMAP) has been synthesized and tested with respect to its catalytic potential in the regioselective acylation of 1,2-diol substrates. The Lewis basicities of the catalysts as quantified through quantum chemical calculations vary due to inductive substituent effects and intramolecular stacking interactions between side chain pi-systems and the pyridinium core ring system. The primary over secondary hydroxyl group selectivities in catalytic acylations of 1,2-diol substrates depend on the size and the steric demand of the Lewis base and the anhydride reagent.

Automated summary

A series of 24 annelated derivatives of 4-diaminopyridine (DMAP) have been synthesized and tested for their catalytic potential in the regioselective acylation of 1,2-diol substrates. The Lewis basicities of the catalysts vary due to inductive substituent effects and intramolecular stacking interactions. The selectivities of primary and secondary hydroxyl groups in catalytic acylations depend on the size and steric demand of the Lewis base and anhydride reagent.