568588-45-4Relevant academic research and scientific papers
Rational tuning chelate size of bis-oxazoline ligands to improve enantioselectivity in the asymmetric aziridination of chalcones
Ma, Linge,Du, Da-Ming,Xu, Jiaxi
, p. 10155 - 10158 (2007/10/03)
Chalcones were asymmetrically aziridinated with [N-(p-toluenesulfonyl) imino]phenyliodinane (PhI=NTs) as a nitrene source under catalysis of CuOTf and a series of cyclohexane-linked bis-oxazolines (cHBOXes), which are chelate size rationally tuned bis-oxazolines. The results indicate that highly enantioselective aziridination of chalcones with up to >99% ee have been achieved under catalysis of (S,S)-1,2-bis[(S)-(4-phenyl)oxazolin-2-yl] cyclohexane, which is the most-matched stereoisomer among cyclohexane-linked bis-oxazolines. It was also found that the enantioselectivity is not substituent-dependent with respect to chalcones in the present case, unlike with 1,8-anthracene-linked bis-oxazolines (AnBOXes).
Asymmetric cyclization-carbonylation of 2-propargyl-1,3-dione
Kato, Keisuke,Tanaka, Maki,Yamamura, Shigeo,Yamamoto, Yasuhiro,Akita, Hiroyuki
, p. 3089 - 3092 (2007/10/03)
The first example of asymmetric cyclization-carbonylation of 2-propargyl-1,3-dione 1 catalyzed by palladium(II) with chiral bisoxazolines (C.H.-BOX) was investigated. The use of bulky alcohols increased the ee of the products 2. The product 2d was converted into bicyclic enones 7 and 8, a useful intermediate for the synthesis of natural products.
