Efficient Nazarov Cyclizations of 2-Alkoxy-1,4-pentadien-3-ones
摘要:
[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.
Hydroxylamine catalyzed Nazarov cyclizations of divinyl ketones
作者:Joseph Z. Hamilton、Nathaniel T. Kadunce、Michael D. McDonald、Laura Rios、Albert R. Matlin
DOI:10.1016/j.tetlet.2015.10.039
日期:2015.11
The first examples of iminium catalyzed Nazarov cyclizations of divinyl ketones are presented. Experiments describing hydroxylamine catalysis of the cyclization of eight alpha-alkoxy divinyl ketones (60-79% yield) and one unactivated divinyl ketone (38% yield) are reported. Phenyl substitution at the beta-position of the divinyl ketone inhibits cyclization, whereas beta-alkyl substituted beta-alkoxy divinyl ketones readily cyclize. (C) 2015 Elsevier Ltd. All rights reserved.
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.
2,2′-Biphenol/B(OH)<sub>3</sub> Catalyst System for Nazarov Cyclization
A novel catalyst system—a combination of the readily available 2,2′-biphenol with the inexpensive, nontoxic, and eco-friendly B(OH)3—promoted the Nazarov cyclization of activated and inactivated divinyl ketones to afford the corresponding cyclopentenones up to 96% yield under, in a cis-selective manner. Compared with the conventional harsh conditions with hazardous reagents, user-friendly method was established with bench-stable and easy-to-handle reagents.