| 摘要 |
A process for enantioselectively epoxidising a prochiral olefin, which process comprises reacting the prochiral olefin with a source of oxygen in the presence of a salen catalyst and a source of an electron donating ligand, characterised in that the donor ligand is isoquinoline N-oxide or a compound having donor ligand activity and having substantially the same solubility characteristics as isoquinoline N-oxide; and compounds used in such process. The catalyst (III) and intermediates for its preparation are also claimed in which M is a transition metal ion; A is a counter-ion if required; B, B', E and E' are independently selected from the group consisting of hydrogen aryl, C1-6 alkyl, silyl or aryl-C1-6 alkyl in which any aryl or alkyl moiety is optionally substituted or B' and B or E' and E together form a C2-6 polymethylene link; with the proviso that only one of the carbons marked with an asterisk is a chiral centre; R1, R2, R3, R4, R5, R6, R7, R8, R9 and R10 are independently hydrogen, alkyl or alkoxy.
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