Highly Enantioselective Carbonyl–Ene Reactions of 2,3‐Diketoesters: Efficient and Atom‐Economical Process to Functionalized Chiral α‐Hydroxy‐β‐Ketoesters
作者:Phong M. Truong、Peter Y. Zavalij、Michael P. Doyle
DOI:10.1002/anie.201402233
日期:2014.6.16
Carbonyl–enereactions of 2,3‐diketoesters catalyzed by [Cu(S,S)‐tBu‐box}](SbF6)2 [box=bis(oxazoline)] generate chiralα‐functionalizedα‐hydroxy‐β‐ketoesters in up to 94 % yield and 97 % ee. The 2,3‐diketoesters are conveniently accessed from the corresponding α‐diazo‐β‐ketoester, and a catalyst loading as low as 1.0 mol % can be achieved.
A novel copper-catalyzedoxidativecyclization of enynes and in situ formed enynes leading to 4-carbonyl-quinolines by using dioxygen as an oxygen source has been developed.
Method of preparing a polyamide acid composition for preparing polyimide
申请人:KANEGAFUCHI KAGAKU KOGYO KABUSHIKI KAISHA
公开号:EP0114059A2
公开(公告)日:1984-07-25
A polyamide acid composition for preparing a polyimide which is improved in the stability in a form of solution and can extend the pot life of the composition comprising a solution of a polyamide acid in an organic solvent, the polyamide acid being a precursor of the polyimide, and an N-substituted heterocyclic compound as a chemical treating agent which can lower a rate of conversion of the polyamide acid to the polyimide. The pot life can be extremely extended to give the composition an enough flowability for a long time without reducing the excellent properties such as a heat resistance of the obtained polyimide.