发明名称 |
Asymmetric ring-closing metathesis reactions involving achiral and meso substrates |
摘要 |
A composition and method for the catalytic conversion of a racemic mixture of dienes to a cyclic olefin by a ring-closing metathesis (RCM) reaction are disclosed. The composition, a transition metal complex with an M=C reaction site, contains a bidentate dialkoxide of at least 80% optical purity. Because the M=C reaction site is of a sufficient shape specificity, conferred in part by the dialkoxide of sufficient rigidity and a M=N-R1 site, reacting the composition with a mixture of two enantiomeric dienes results in an olefin metathesis product that has at least a 50% enantiomeric excess of one enantiomer in the mixture. A method is also provided for reacting a composition with a racemic diene mixture to generate a metathesis product that has an enantiomeric excess of at least 50%. Methods are also provided for catalytic enantioselective desymmetrization. One method involves an olefin metathesis reaction with a molecular substrate having a plane of symmetry to form a product free of a plane of symmetry. Another method provides a desymmetrization reaction to occur in the absence of solvent. A method for producing quaternary carbon centers through a desymmetrization reaction is also described.
|
申请公布号 |
US6346652(B1) |
申请公布日期 |
2002.02.12 |
申请号 |
US19980114692 |
申请日期 |
1998.07.13 |
申请人 |
MASSACHUSETTS INSTITUTE OF TECHNOLOGY |
发明人 |
SCHROCK RICHARD R.;HOVEYDA AMIR H. |
分类号 |
C07B53/00;C07B57/00;C07F7/18;C07F11/00;(IPC1-7):C07C6/02;C07D307/00 |
主分类号 |
C07B53/00 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|