Formal Homo-Nazarov and Other Cyclization Reactions of Activated Cyclopropanes
作者:Filippo De Simone、Tanguy Saget、Fides Benfatti、Sofia Almeida、Jérôme Waser
DOI:10.1002/chem.201102583
日期:2011.12.16
Replacing one of the vinylgroups by a cyclopropane leads to a formal homo‐Nazarov process for the synthesis of cyclohexenones. In contrast to the Nazarov reaction, the cyclization of vinyl‐cyclopropyl ketones is a stepwise process, often requiring harsh conditions. Herein, we describe two different approaches for further polarization of the three‐membered ring of vinyl‐cyclopropyl ketones to allow the
Indium-Catalyzed Homo-Nazarov Cyclizations of Alkenyl Cyclopropyl Ketones
作者:Dadasaheb V. Patil、Lien H. Phun、Stefan France
DOI:10.1021/ol102497w
日期:2010.12.17
Herein, an efficient Lewis acid catalyzed protocol for the homo-Nazarov cyclizations of alkenyl cyclopropylketones is reported. Alkenes bearing β-hydrogens (or silyl groups) provide 1.5:1 mixtures of methylene cyclohexenols and cyclohexenones. When no β-hydrogens (or silyl groups) are present, only cyclohexenones are observed. Products are rapidly formed in good to high yields (up to 93%) under mild