Impact of Catalyst Deuteration on the Reactivity of Chiral Phase-Transfer Organocatalysts

Site-specifically deuterated organocatalysts were prepared and found to show improved reactivity over the non-deuterated analogs. Two privileged C-2-symmetric chiral binaphthyl-modified tetraalkylammonium salts were selected for this study. The stability of these phase-transfer catalysts was generally improved by site-specific deuteration, though the degree of improvement was structure dependent. In particular, a large secondary kinetic isotope effect was observed for the tetradeuterated phase-transfer catalyst. The performance of these deuterated catalysts in the asymmetric catalytic alkylation of amino acid derivatives was better than that of non-deuterated analogs at low catalyst loadings. The results suggest that catalyst deuteration is a promising strategy for enhancing the stability and performance of organocatalysts.

Automated summary

Site-specifically deuterated organocatalysts exhibit enhanced reactivity compared to non-deuterated analogs in the asymmetric catalytic alkylation of amino acid derivatives. The stability of phase-transfer catalysts can be improved by site-specific deuteration, with a significant secondary kinetic isotope effect observed for tetradeuterated catalysts. These findings suggest that catalyst deuteration is a promising strategy to enhance the stability and performance of organocatalysts.