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.
Reactions of organic halides with olefins under Ni o -catalysis. Formal addition of hydrocarbons to CC-double bonds
作者:Reiner Sustmann、Peter Hopp、Peter Holl
DOI:10.1016/s0040-4039(01)80283-5
日期:——
The reaction of various types of organic halides with electron deficient olefins under the influence of NiCl2 × 6 H2O in the presence of zinc and pyridine leads to formal addition products of hydrocarbons to CC-double bonds in good yield.
在锌和吡啶的存在下,各种类型的有机卤化物与缺电子的烯烃在NiCl 2 ×6 H 2 O的作用下反应,可将烃正式加成产物成CC-双键。
Synthesis of ketols of the natural pyrethrins
作者:L. Crombie、P. Hemesley、Gerald Pattenden
DOI:10.1039/j39690001016
日期:——
A stereospecific five-stage synthesis of (±)-cis-pyrethrolone is described, involving cis-octa-1,3-dien-7-one as the key intermediate. The ethylene acetal of this ketone was made by a Wittig reaction, under salt-free condiditions, with vaporised acraldehyde. The overall yield for the synthesis was 21%, and it provides highly pure (pm;)-cis-pyrethrolone for the first time. The material is spectrally