Addition of ketone enolates to π-allylpalladlum compounds. Stereochemistry and scope of the reaction
作者:Björn Akermark、Anny Jutand
DOI:10.1016/s0022-328x(00)93458-2
日期:1981.9
Conditions have been developed for the addition of ketone enolates to π-allylpaliadium systems, A stereochemica1 study has shown that the enolate adds from the face of the π-allyl system opposite to palladium.
The present invention relates to processes for preparing certain 2-pyridones and 2-pyridinols, to novel compounds of these two types and to their use as biologically active compounds, in particular for controlling harmful microorganisms in crop protection, in the medicinal field and in the protection of materials.
Reactivite des acylaldocetenes dans la cycloaddition intramoleculaire
作者:F. Leyendecker
DOI:10.1016/0040-4020(76)80048-8
日期:1976.1
The reactivity of acylaldoketenes, short-lived species generated by flash thermolysis of ϵ-ethylenic β-ketoesters, in [2 + 2] intramolecular cycloaddition reactions, has been examined. The observed regiospecificity can be rationalized by frontier orbital theory.
Intramolecular Polar [4<sup>⊕</sup>+2] Cycloadditions of Aryl-1-aza-2-azoniaallene Salts: Unprecedented Reactivity Leading to Polycyclic Protonated Azomethine Imines
作者:Daniel A. Bercovici、Jodi M. Ogilvie、Nikolay Tsvetkov、Matthias Brewer
DOI:10.1002/anie.201306553
日期:2013.12.9
Charged up: In the first example of the title salts undergoing a [4⊕+2] cycloaddition reaction, the azo bond and one aromatic π bond make up the 4π component. This reaction appears to be concerted and provides high yields of protonatedazomethineimine products. Substituted alkenes provided products containing all‐carbon or nitrogen‐bearing quaternary centers in high yield.
Preparation of unsaturated α,α-dichloro acid chlorides and intramolecular [2 + 2] cycloadditions of the α-chloroketenes reductively generated from them. Effect of double bond geometry on the cycloaddition
作者:Barry B. Snider、Marleen Walner
DOI:10.1016/s0040-4020(01)80143-5
日期:1989.1
Reduction of unsaturatedα,α-dichloracid chlorides with zinc dust in THF at reflux generates an unsaturated α-chloroketene which undergoes an intramolecular [2 + 2] cycloaddition in good yield. This reaction can be used with three carbon tethers to prepare 5-chlorobicyclo[3.2.0]heptan-6-ones and 1-chlorobicyclo[3.1.1]heptan-6-ones but fails with larger tethers. Unsaturated ketenes 18 and 28, with a