Davies David L, Fawcett John, Garratt Shaun A, Russell David R
Department of Chemistry, University of Leicester, Leicester, UK LE1 7RH.
Dalton Trans. 2004 Nov 7(21):3629-34. doi: 10.1039/B408921A. Epub 2004 Oct 1.
Half-sandwich complexes [RhCl(pymox)Cp*]SbF(6)(pymox = pyridyloxazoline) have been synthesised as single diastereomers. Treatment of these with AgSbF(6) generates dications Rh(OH(2))(pymox)Cp* which are fluxional at room temperature and which are enantioselective catalysts for the Diels-Alder reaction of methacrolein and cyclopentadiene. Treatment of the dication Rh(OH(2))((i)Pr-pymox)Cp* with X gives [RhX((i)Pr-pymox)Cp*][SbF(6)](X = Br, I) as single diastereomers whilst reaction with 4-Mepy (4-methylpyridine) gives [Rh(4-Mepy)((i)Pr-pymox)Cp*][SbF(6)] as a mixture of diastereomers. Two complexes, [RhCl((i)Pr-pymox)Cp*]SbF(6) and [RhCl(Bz-pymox)Cp*]SbF(6) have been characterised by X-ray crystallography.
已合成出单一对映异构体的半夹心配合物[RhCl(pymox)Cp*][SbF₆](1 - 7)(pymox = 吡啶基恶唑啉)。用AgSbF₆处理这些配合物会生成二价阳离子[Rh(OH₂)(pymox)Cp*]²⁺,其在室温下具有流动性,并且是甲基丙烯醛与环戊二烯的狄尔斯 - 阿尔德反应的对映选择性催化剂。用[X]⁻处理二价阳离子[Rh(OH₂)((i)Pr - pymox)Cp*]²⁺会得到单一对映异构体的[RhX((i)Pr - pymox)Cp*][SbF₆](X = Br, I),而与4 - Mepy(4 - 甲基吡啶)反应则得到非对映异构体混合物的[Rh(4 - Mepy)((i)Pr - pymox)Cp*][SbF₆]。已通过X射线晶体学对两种配合物[RhCl((i)Pr - pymox)Cp*]SbF₆和[RhCl(Bz - pymox)Cp*]SbF₆进行了表征。