Enantioselective S-Alkylation of Sulfenamides by Phase-Transfer Catalysis.

ABSTRACT: A general phase-transfer catalyst (PTC) mediated enantioselective alkylation of N-acylsulfenamides is reported. Essential to achieving high selectivity was the use of the triethylacetyl sulfenamide protecting group along with aqueous KOH as the base under biphasic aqueous conditions to enable the reaction to be performed at -40 °C. With these key parameters, enantiomeric ratios up to 97.5 : 2.5 at the newly generated chiral sulfur center were achieved with an inexpensive cinchona alkaloid derived PTC. Broad scope and excellent functional group compatibility was observed for a variety of S-(hetero)aryl and branched and unbranched S-alkyl sulfenamides. Moreover, to achieve high selectivity for the opposite enantiomer, a pseudoenantiomeric catalyst was designed and synthesized from inexpensiv

SUBMITTER: Champlin AT 

PROVIDER: S-EPMC11514311 | biostudies-literature | 2024 Oct

REPOSITORIES: biostudies-literature