ol7b02722_si_001.pdf (6.01 MB)
Tetraarylphosphonium Salt-Catalyzed Synthesis of Oxazolidinones from Isocyanates and Epoxides
journal contribution
posted on 2017-10-17, 16:22 authored by Yasunori Toda, Shuto Gomyou, Shoya Tanaka, Yutaka Komiyama, Ayaka Kikuchi, Hiroyuki SugaPreparation of a
range of oxazolidinones, including enantioenriched N-aryl-substituted oxazolidinones, in which tetraarylphosphonium
salts (TAPS) catalyze the [3 + 2] coupling reaction of isocyanates
and epoxides effectively, is described. The key finding is a Brønsted
acid/halide ion bifunctional catalyst that can accelerate epoxide
ring opening with high regioselectivity. Mechanistic studies disclosed
that the ylide generated from TAPS, along with the formation of halohydrins,
plays a crucial role in the reaction with isocyanates.