Enantioselective Catalysts for the Diels–Alder Reaction between Methacrolein and Cyclopentadiene Based on the Chiral Fragment (η5-C5Me5)M(chiral diphosphane) (M = Rh, Ir)
摘要:
The aqua complexes [(eta(5)-C5Me5)M(PP*)-(H2O)][SbF6](2) (M = Rh, Ir; PP* = chiral diphosphane) (1-10) are prepared and characterized. These complexes efficiently catalyze the Diels-Alder reaction between methacrolein and HCp with enantioselectivities of up to 96% e.e. The norphos complexes 9 and 10, which are obtained as diastereomeric mixtures of the two epimers at the metal, afford the highest e.e. values. The intermediate complexes [(eta(5)-C5Me5)M(PP*)-(methacrolein)] [SbF6](2) (11-20) are also isolated and characterized, including the molecular structure determination of the [(eta(5-CMe5)-Me-5)M(benphos)(methacrolein)][SbF6](2) (M = Rh (13), Ir (14)) derivatives. An NMR study of the reactivity of the metallic intermediates under catalytic conditions explains the high enantioselectivities achieved with the norphos systems.
Optisch aktive 1,2-Bis(diphenylphosphino)-verbindungen, diese als chirale Liganden enthaltende Metallkomplexe und deren Verwendung
申请人:Degussa Aktiengesellschaft
公开号:EP0031877B1
公开(公告)日:1983-02-02
US4356324A
申请人:——
公开号:US4356324A
公开(公告)日:1982-10-26
Enantioselective Catalysts for the Diels–Alder Reaction between Methacrolein and Cyclopentadiene Based on the Chiral Fragment (η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)M(chiral diphosphane) (M = Rh, Ir)
作者:Daniel Carmona、Fernando Viguri、Ainara Asenjo、M. Pilar Lamata、Fernando Lahoz、Pilar Garcı́a-Orduña、L. A. Oro
DOI:10.1021/om200859z
日期:2011.12.26
The aqua complexes [(eta(5)-C5Me5)M(PP*)-(H2O)][SbF6](2) (M = Rh, Ir; PP* = chiral diphosphane) (1-10) are prepared and characterized. These complexes efficiently catalyze the Diels-Alder reaction between methacrolein and HCp with enantioselectivities of up to 96% e.e. The norphos complexes 9 and 10, which are obtained as diastereomeric mixtures of the two epimers at the metal, afford the highest e.e. values. The intermediate complexes [(eta(5)-C5Me5)M(PP*)-(methacrolein)] [SbF6](2) (11-20) are also isolated and characterized, including the molecular structure determination of the [(eta(5-CMe5)-Me-5)M(benphos)(methacrolein)][SbF6](2) (M = Rh (13), Ir (14)) derivatives. An NMR study of the reactivity of the metallic intermediates under catalytic conditions explains the high enantioselectivities achieved with the norphos systems.