Synthesis of Pyridines and Pyrazines Using an Intramolecular Hydroamination-Based Reaction Sequence
作者:Toni Rizk、Eric J.-F. Bilodeau、André M. Beauchemin
DOI:10.1002/anie.200903922
日期:2009.10.19
A management issue! Various pyridines and pyrazines can be efficiently accessed from simple acyclic precursors using an intramolecularhydroamination/isomerization/aromatization sequence (see scheme). p‐Toluenesulfonic acid (2 mol %) is used to catalyze this novel alkyne annulation, in which the oxime group allows for a subsequent redox‐neutral aromatization step to occur.
Stereoselective Synthesis of Medium-sized Cyclic Compounds through the Intramolecular Michael-type Reaction Utilizing Alkyne–Hexacarbonyldicobalt Complex Formation
作者:Kennichi Inaba、Jun Takaya、Nobuharu Iwasawa
DOI:10.1246/cl.2007.474
日期:2007.3.5
Alkyne–hexacarbonyldicobalt complexes having silyl enol ether and electron-deficient alkene moieties on opposite ends were treated with MeAlCl2 in the presence of 2,6-di-t-butylpyridine in CH2Cl2 t...
Synthesis of Cyclohexanones through a Catalytic Cationic Cyclization of Alkynols or Enynes
作者:Pedro Alonso、Raquel Fontaneda、Pilar Pardo、Francisco J. Fañanás、Félix Rodríguez
DOI:10.1021/acs.orglett.8b00437
日期:2018.3.16
A novel procedure for the synthesis of cyclohexanones from alkynol or enyne derivatives through a cationic cyclization has been developed. The key points to obtain the six-membered ring derivatives are the use of starting materials containing a terminal alkyne, the use of tetrafluoroboric acid as a promoter of the cationic cyclization, and the appropriate selection of 1,1,1,3,3,3-hexafluoropropan-2-ol
Synthesis and Applications of Cyclohexenyl Halides Obtained by a Cationic Carbocyclisation Reaction
作者:Pedro Alonso、Pilar Pardo、Raquel Fontaneda、Francisco J. Fañanás、Félix Rodríguez
DOI:10.1002/chem.201702490
日期:2017.9.21
alkenyl halides (mainly fluorides, chlorides and bromides) from alkynol or enyne derivatives by an acid‐mediated cationic cyclisation reaction is disclosed. This high‐yielding, scalable and technically simple method complements and challenges conventional methodologies. This study includes the development of biomimetic cationic cyclisation reactions of polyenyne derivatives to give interesting halogen‐containing
Synthesis of Cyclic Alkenyl Triflates by a Cationic Cyclization Reaction and its Application in Biomimetic Polycyclizations and Synthesis of Terpenes
作者:Pedro Alonso、Pilar Pardo、Alicia Galván、Francisco J. Fañanás、Félix Rodríguez
DOI:10.1002/anie.201508077
日期:2015.12.14
cyclic alkenyl triflates. This new atom‐economical process is high yielding, scalable, technically very simple, proceeds without the need of any metallic reagent or catalyst, and more importantly, it complements and challenges conventional methodologies. We have also developed new biomimetic cationic cyclization reactions to yield interesting polycyclic compounds. As a demonstration of the potential of