Premium
Chiral Ruthenium‐Oxo Complexes for Enantioselective Epoxidation of trans ‐Stilbene
Author(s) -
Yu WingYiu,
Fung WaiHong,
Zhu JiaLing,
Cheung KungKai,
Ho KwokKeung,
Che ChiMing
Publication year - 1999
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.199900050
Subject(s) - chemistry , ruthenium , enantioselective synthesis , styrene , moiety , alkene , medicinal chemistry , stereochemistry , catalysis , organic chemistry , copolymer , polymer
Two oxoruthenium(IV) complexes containing C 2 symmetric 1,1′‐biisoquinoline (biqn) and ( R,R )‐3,3′‐(1,2‐dimethylethylenedioxy)‐2,2′‐bipyridine (diopy*) were prepared, and both are active oxidants for alkene epoxidations. The oxidation of styrene and cis ‐ and trans ‐β‐methylstyrenes by [(Cn)(diopy*)‐Ru IV (O)](ClO 4 ) 2 did not proceed enantioselectively, but the same oxidant can attain a moderate enantioselectivity of 33%ee for the trans ‐stilbene oxidation to trans ‐stilbene oxide. A head‐on approach model, where the C=C is directed from the top to the O=Ru moiety, is proposed to account for the facial differentiation of the trans ‐stilbene oxidation.