New Synthetic Approach to Cyclopenta-Fused Heterocycles Based upon a Mild Nazarov Reaction
作者:Ernesto G. Occhiato、Cristina Prandi、Alessandro Ferrali、Antonio Guarna、Paolo Venturello
DOI:10.1021/jo034939p
日期:2003.12.1
role in forcing the conrotatory process to take place in one sense only: allowing the synthesis of diastereomerically pure compounds to be realized. Because different patterns of substitution on the heterocycle are compatible with the reaction conditions, the methodology developed could be very useful for the synthesis of natural products and biologically active compounds containing cyclopenta-fused O-
Iodolium salts as halogen-bond donor catalysts in the Nazarov cyclization: the molecular oxygen enigma
作者:Avery J. To、Graham K. Murphy
DOI:10.1039/d2nj02731c
日期:——
Nazarov cyclizations of activated precurosrs are achieved under iodolium catalysis, provided that oxygen is present for catalyst activation and turnover.
Efficient Nazarov Cyclizations of 2-Alkoxy-1,4-pentadien-3-ones
作者:Guangxin Liang、Stefan N. Gradl、Dirk Trauner
DOI:10.1021/ol036019z
日期:2003.12.1
[GRAPHICS]Expeditious and high-yielding Nazarov cyclizations of 2-alkoxy-1,4-pentadien-3-ones are described. An example of a catalytic asymmetric Nazarov cyclization is presented.
Nazarov-type Reactions in Water
作者:Masaya Kokubo、Shū Kobayashi
DOI:10.1002/asia.200800461
日期:2009.4.6
AbstractDifferent in water! We have developed Nazarov‐type reactions in water. Different reaction courses compared with those in organic solvents are observed in water. In the presence of a scandium based, surfactant‐type catalyst, water‐trapping products are obtained exclusively. The results presented are unprecedented and provide a valuable extension to information available regarding organic reactions in water.magnified image
4-Toluenesulfonic acid: an environmentally benign catalyst for Nazarov cyclizations
An efficient metal-free catalytic protocol for the electrocyclization of alpha-alkoxydienones to cyclopentenones (Nazarov reaction) in near to quantitative yields is described. The key parameters are the use of inexpensive 4-toluenesulfonic acid in 5 mol % at room temperature in acetonitrile or under solvent-free conditions. The versatility of the transformation is demonstrated with unpolarized dienones with good regioselectivities and excellent yields. (c) 2008 Elsevier Ltd. All rights reserved.