PROCESS FOR USE IN THE PREPARATION OF OXIRANES FROM ALKENES, AND CATALYSTS FOR USE THEREIN

摘要

There is provided a process for the preparation of oxiranes wherein an optionally substituted alkene is reacted in the presence of a chiral catalyst, an oxidant and an organic solvent characterised in that the oxidant is at least partially soluble in the organic solvent and the oxidant displays low reactivity towards the alkene in the absence of the catalyst. The optionally substituted alkene is preferably an alkene of formula (1): wherein: R<1-4 >each independently are hydrogen, an optionally substituted aromatic or is saturated hydrocarbyl, an optionally substituted hetrocyclyl, an optionally substituted aromatic or saturated hydrocarbyloxy, an optionally substituted aromatic or saturated hydrocarbylamino, an optionally substituted aromatic or saturated hydrocarbyloxycarbonyl, an optionally substituted aromatic or saturated hydrocarbylaminocarbonyl, nitrile, halide or one or more of R<1> & R<2>, R<2> & R<3> , R<3> & R<4> , R<1> & R<4> optionally being linked in such a way as to form an optionally substituted ring(s). The oxidant is preferably an oxidant of formula (2): A<+> HSO<5- >wherein A<+> is a counterion capable of conferring organic solvent solubility. Preferred chiral catalysts of formula (4): wherein: R<11> and R<12> are each independently an optionally substituted hydrocarbyl group or R<11> & R<12> are linked in such a way as to form an optionally substituted ring(s); R<13> is hydrogen or an optionally substituted hydrocarbyl group; R<14> is an optionally substituted hydrocarbyl group; R<17> is hydrogen or an optionally substituted hydrocarbyl group; R<15> and R<16> each independently are hydrogen or an optionally substituted hydrocarbyl group; and 30 is a counterion; * is a chiral centre; and *' is a chiral centre when R<17> is not hydrogen are provided.