Rhodium-Catalyzed Asymmetric Ring Opening Reactions of Oxabicyclic Alkenes: Application of Halide Effects in the Development of a General Process
作者:Mark Lautens、Keith Fagnou、Dingqiao Yang
DOI:10.1021/ja034845x
日期:2003.12.1
effects in the rhodium-catalyzed asymmetric ringopening reaction of oxabicyclicalkenes. By employing halide and protic additives, the catalyst poisoning effect of aliphatic amines is reversed allowing the amount nucleophile to react in high yield and ee. Second, by simply changing the halide ligand on the rhodium catalyst from chloride to iodide, the reactivity and enantioselectivity of reactions employing
我们已经在铑催化的氧杂双环烯烃的不对称开环反应中证明了卤化物效应。通过使用卤化物和质子添加剂,脂肪胺的催化剂中毒效应被逆转,允许一定量的亲核试剂以高产率和 ee 反应。其次,通过简单地将铑催化剂上的卤化物配体从氯化物变为碘化物,使用芳香胺、丙二酸酯或羧酸盐亲核试剂的反应的反应性和对映选择性得到显着提高。第三,通过应用卤化物效应和更强制的反应条件,反应性较低的氧杂二环 [2.2.1] 底物反应生成合成有用的对映体富集的环己烯醇产物。
Rhodium-catalysed asymmetric ring opening of oxabicyclic alkenes with heteroatom nucleophiles
high regio- and diastereoselectivity (>99:1), and excellent enantioselectivity (up to 99%ee). Symmetrical substitution patterns on the aromatic ring of the oxabenzonorbornadienes had no effect on the course of the reaction nor the enantioselectivity. The reaction produces an unusual stereochemical outcome for oxabicyclicringopenings since the trans rather than the cis product is formed. Very low catalyst
Rhodium-Catalyzed Asymmetric Ring Opening of Oxabicyclic Alkenes with Phenols
作者:Mark Lautens、Keith Fagnou、Mark Taylor
DOI:10.1021/ol005729r
日期:2000.6.1
The scope of the rhodium-catalyzed asymmetric ringopening reaction of oxabenzonorbornadiene has been extended to include phenolic nucleophiles. The enanatioenriched, functionalized dihydronaphthalene products are highly valuable intermediates for which no other practical methods of preparation are available. A new catalyst system has been developed which allows the use of less reactive o-halophenols
Novel compounds and a novel process for their preparation
申请人:Fagnou Keith
公开号:US20050014721A1
公开(公告)日:2005-01-20
The present invention is directed to a procedure for making an enantiomerically enriched compound containing a hydronaphthalene ring structure. The process involves reacting oxabenzonorbornadienes with nucleophiles using rhodium as a catalyst and in the presence of a phosphine ligand. The compounds synthesized may be used in pharmaceutical preparations for the treatment of a variety of diseases and conditions.
Novel hydronaphthalene compounds, prepared by a rhodium catalysed ring opening reaction in the presence of phosphine ligand
申请人:AstraZeneca AB
公开号:EP1498406A1
公开(公告)日:2005-01-19
The present invention is directed to a procedure for making an enantiomerically enriched compound containing a hydronaphthalene ring structure. The process involves reacting oxabenzonorbornadienes with nucleophiles using rhodium as a catalyst and in the presence of a phosphine ligand. The compounds synthesized may be used in pharmaceutical preparations for the treatment of a variety of diseases and conditions.