ChalBondCat

Chiral tertiary amine Lewis bases are proficient catalysts for a range of enantioselective transformations, with isothioureas regarded as versatile catalysts within this field. The observed reactivity and selectivity in isothiourea-catalyzed processes is hypothesized to primarily derive from an intramolecular 1,5-O---S interaction within key reaction intermediates, identified through computation and solid-state crystallographic analysis. Recognition of this 1,5-O---S motif as a chalcogen bond offers significant opportunities for exploitation and development. Building on these ideas, this proposal will develop a range of catalytically effective isochalcogenourea Lewis bases alongside a quantitative underpinning knowledge of their fundamental physical properties (such as nucleophilicity, Lewis basicity, pKaH). They will be benchmarked for catalytic activity (via kinetic analysis) and enantioselectivity, with the aim to develop a series of catalysts that operate effectively at ppm concentrations. The developed catalysts will subsequently be applied in a dynamic enantioselective reaction process to allow catalytic control over the absolute configuration of P(V) stereogenicity.