A Synthetic and Mechanistic Investigation of the Chromium Tricarbonyl-Mediated Masamune–Bergman Cyclization. Direct Observation of a Ground-State Triplet<i>p</i>-Benzyne Biradical
作者:Kai E. O. Ylijoki、Séverine Lavy、Angelika Fretzen、E. Peter Kündig、Théo Berclaz、Gérald Bernardinelli、Céline Besnard
DOI:10.1021/om300427j
日期:2012.8.13
bond formation from an η6-enediyne complex is the lowest-energy path, forming a metal-bound p-benzyne biradical. NMR spectroscopy suggests that enediyne alkene coordination occurs in preference to alkyne coordination, forming a THF-stabilized olefinintermediate; subsequent alkyne coordination leads to cyclization. While biradical quenching occurs rapidly and primarily via the singlet biradical, the
Kündig, E. Peter; Ripa, Alberto; Liu, Ronggang, Organometallics, 1993, vol. 12, # 9, p. 3724 - 3737
作者:Kündig, E. Peter、Ripa, Alberto、Liu, Ronggang、Amurrio, David、Bernardinelli, Gerald
DOI:——
日期:——
Asymmetric Addition of Organolithium Reagents to Prochiral Arene Tricarbonylchromium Complexes
作者:David Amurrio、Karl Khan、E. Peter Kündig
DOI:10.1021/jo960070h
日期:1996.1.1
Organometallic Helices: The Mechanism of Formation of “Metallospiralenes”
作者:Jean-Pierre Djukic、Aline Maisse-François、Michel Pfeffer、Karl Heinz Dötz、André De Cian、Jean Fischer
DOI:10.1021/om0006920
日期:2000.12.1
insertion of a Ph(MeO)C: moiety into the CAr−Mn bond. X-ray diffraction analyses reveal that the two compounds are pseudoconformers which differ from the position of the Mn(CO)3 moiety: in one compound, the Mn(CO)3 group is located close to the Cr(CO)3 group, while in the other compound, it is part of a nearly planar six-membered manganacyclic ring coplanar with the π-coordinated arene. These results
形成的机制的一个完整的调查螯合顺-facial的异苄基配合物,也被称为铬/锰spiralenes,呈现。金属卡宾物种的中间光谱证据由13建立13 C NMR光谱。在卡宾碳原子上的取代模式的性质显示出在螺旋烯形成的立体选择性中起决定性作用。将烷基锂试剂和MeOTf顺序添加到一系列环锰化的2-苯基吡啶衍生物中,得到两种异构螺旋烯的混合物,其中一对实例已通过X射线衍射进行了表征。结构上更灵活的异双金属异构体显示出与苄基C-Mn键均溶性破坏时形成的双自由基物种可能介导的相互转化能力。对2-恶唑啉基衍生物的研究揭示了螺旋烯非对映选择性形成的起源。顺序加入PhLi和MeOTf到一个cyclomanganated 2 - [(η 6 -4-甲苯基)的Cr(CO)3] -2-恶唑啉衍生物提供两种产物的混合物,两者都是由于将Ph(MeO)C:部分插入C Ar -Mn键而产生的。X射线衍射分析表明,这两种化合