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Anion alkoksyallenowy w syntezie związków naturalnych i ich analogów

Busiak B., Utecht G., Jasiński M.

Wiadomości Chemiczne

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2016

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[Z] 70, 1-2

3--23

EN

Among diverse systems containing multiple bonds, cumulenes are recognized as the most reactive derivatives towards both nucleophilic and electrophilic agents, and for this reason, they are considered as important class of substrates for organic synthesis. Over the last three decades alkoxyallenes have been demonstrated as highly useful C3-building blocks for the construction of numerous N-, O-, and S-containing heterocycles, including enantiomerically pure compounds. Special attention has been paid to lithiated alkoxyallenes as suitable nucleophiles for the reactions with alkyl halides, strained heterocycles, carbonyl compounds and their derivatives. The presence of the allene unit in the initially formed adducts opens up several possibilities in the preparation of more complex systems. In this review, selected applications of lithiated alkoxyallenes in the synthesis of natural products and their analogues are discussed.

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Reactions of ‘Cage’ Dione with Primary Amines; Revision of an Earlier Report

Romański J.

Polish Journal of Chemistry

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2007

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Vol. 81, nr 2

187-191

EN

Reactions of pentacyclo[5.4.0.02,6.03,10.05,9]undecane-8,11-dione (1, ‘cage’ dione) with primary amines (i.e. benzylamine, aniline, methylamine and 2-aminoethanol) leading to the adducts 4a–d in good yields are described. In all cases the transannular cyclization process was observed and oxa-bridged products 4a–d were obtained. Isolated compounds were identified as hemiacetals or their internal salts. The type of the formed product is dependent on basicity of the used amines. Subsequent dehydration of the initially obtained adducts in boiling benzene led to monoimines 3a–d..

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Sole winylofosfoniowe w syntezie organicznej

Mazurkiewicz R., Fryczkowska B., Gabański R.

Wiadomości Chemiczne

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2005

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[Z] 59, 3-4

249--274

EN

Vinylphosphonium salts are known for more than a century, but they started to attract significant attention of organic chemists only since 1964 when Schweizer demonstrated that the Michael addition of a nucleophile with a carbonyl function to vinylphosphonium salts results in phosphorus ylides, which can undergo the intramolecular Wittig reaction to carbo- and heterocyclic systems. The main synthetic routes to vinylphosphonium salts and a variety of their applications in organic syntheses are considered in detail in this review. Particular attention is given to the application of vinylphosphonium salts as versatile building blocks for syntheses of carbo- or heterocyclic systems in reactions with carbon, oxygen sulphur or nitrogen nucleophiles containing in a molecule a carbonyl function.

4

Nucleophilic additions in Cu(II), Ni(II), Co(II) pseudohalide-4-halogenopyrazole systems

Hvastijova M., Kohout J., Mroziński J., Jager L.

Polish Journal of Chemistry

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1999

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vol. 73 nr 2

271-278

EN

From M(II)-Y--4-X-pz systems, where M=Cu, Ni, Co; Y=NCO, C(CN)3, N(CN)2; X=Cl, Br, I (pz = pyrazole), new compounds of the type [MY2(4-X-pz)2] and [M(4-X-pz×Y)2] have been prepared. Compounds [M(4-X-pz×Y)2] arise by nucleophylic addition of imine nitrogen from 4-X-pz to cyano carbon of the pseudohalide under formation of five-membered metallocycle. The influence of X substituent on the course of this reaction with various M(II) and Y was investigated. An uncomplete course of nucleophilic addition is revealed by formation of mixed products, consisting of [MY2(4-X-pz)2] and [M(4-X-pz×Y)2]. All compounds were studied by infrared and electronic spectroscopy and probable structures were assigned to the relevant species.