ChemInform Abstract: New Method for the Synthesis of Monoalkyl‐Substituted Cyclobutanes.

Джемилев, У. М.; Ибрагимов, А. Г.; Zolotarev, A. P.; Муслухов, Р. Р.; Толстиков, Г. А.

doi:10.1002/chin.199018139

Cited by 6 publications

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“…The yields of organomagnesium compounds were determined by GLC analysis of the corresponding deuterium derivatives. Compounds IV-VI [25], Xa, Xb, XIa, XIb [26], XIIIa, XIIIb [27], XVIIa [28], XVIIb [29], XIXa, XIXb, [30], and XXIIa-XXIId [20] were identified by comparing their physical properties and spectral parameters with those of authentic samples.…”

Section: Methodsmentioning

confidence: 99%

“…The extract was dried over MgSO 4 and evaporated, and the residue was subjected to fractional distillation under reduced pressure. 13 C NMR spectrum (C 6 D 6 ), δ C , ppm: 14.18 (C 11 , C 17 ), 22.72 (C 10 , C 16 ), 28.67 (C 3 , C 4 ), 28.71 (C 7 , C 13 ), 29.50 (C 8 , C 14 ), 32.00 (C 9 , C 15 ), 142.84 (C 6 , C 12 ), 188.30 (C 2 , C 5 ).…”

Section: Reaction Of 12-dienes With Etmgbr In the Presence Of Activamentioning

confidence: 99%

“…13 C NMR spectrum (C 6 D 6 ), δ C , ppm: -1.13 (MgCH 2 ), 12.27 (MgCH 2 CH 3 ), 14.18 (C 1 , C 16 ), 19.89 (C 8 , C 9 ), 22.72 (C 2 , C 15 ), 28.71 (C 5 , C 12 ), 29.50 (C 4 , C 13 ), 32.00 (C 3 , C 14 ), 142.84 (C 6 , C 11 ), 166.36 (C 7 , C 10 ).…”

Section: 5-dihexylidenemagnesacyclopentane (Xxa)mentioning

confidence: 99%

“…C NMR spectrum, δ C , ppm: 11.40 (C 1 ), 14.11 (C 9 ), 18.91 t (J CD = 19.5 Hz),22.72 (C 8 ), 27.10 (C 5 ),29.51 (C 2 ),29.71 (C 6 ), 31.99 (C 7 ), 34.36 (C 4 ), 37.11 (C 3 ).…”

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Cyclomagnesation of Olefins with Ethylmagnesium Bromide in the Presence of Titanium Complexes

et al. 2005

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Cyclomagnesation of terminal and cyclic olefins and 1,2-dienes with RMgHlg and R 2 Mg in the presence of dichloro(dicyclopentadienyl)titanium(IV) gives non-Grignard cyclic and acyclic organomagnesium compounds. The reaction direction depends on the structure of unsaturated initial compound. The most probable reaction mechanism is discussed.In 1989, we reported [1] on the cyclomagnesation of olefins with RMgR' (R' = Alk, Hlg) in the presence of Cp 2 ZrCl 2 as catalyst, which afforded 1,4-dimagnesium compounds and/or magnesacyclopentanes. These studies were subsequently developed in [2][3][4][5][6][7][8][9]. According to the data of [3,6,8], depending on the conditions, the cyclomagnesation process can be accompanied by carbomagnesation [10][11][12][13][14] which involves formation of zirconacyclopentane intermediates. The yields and ratio of cyclo-and carbomagnesation products depends on the solvent nature, temperature, and initial reactant ratio [3,8]. As a rule, the reaction is catalyzed by zirconium complexes [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. We have found no published data on the use of coordination compounds derived from other transition metals to catalyze cyclomagnesation.With the goal of extending the scope of application of catalytic cyclomagnesation of unsaturated compounds with organomagnesium reagents and searching for new catalysts capable of promoting such reactions, we examined reactions of ethylmagnesium bromide and diethylmagnesium (EtMgR; R = Br, Et) with olefins (1-octene, allylbenzene, styrene, and endo-dicyclopentadiene) in the presence of catalytic systems on the basis of Ti, Hf, Fe, Co, Ni, Pd, and Rh, i.e., transition metals whose coordination compounds are widely used to catalyze various transformations of olefins, dienes, and acetylenes. Preliminary experiments showed that the maximal yields of the cyclomagnesation products are attained in the presence of titanium complexes, in particular Cp 2 TiCl 2 . Therefore, all subsequent experiments on cyclomagnesation of the above listed olefins were performed with the use of Cp 2 TiCl 2 as catalyst.Depending on the substrate nature, the reactions with EtMgBr and Et 2 Mg in the presence of Cp 2 TiCl 2 gave cyclo-, carbo-, and hydromagnesation products. Styrene reacted with EtMgBr in the presence of Cp 2 TiCl 2 (20°C, 20 h, THF, PhCH=CH 2 -EtMgBr-[Ti] ratio 1 : 2 : 0.05) to afford a mixture of mono-and diphenyl-substituted magnesacyclopentanes and/or (in keeping with the Schlenk equilibrium) 1,4-dimagnesium derivatives I-III [3,8]. Deuterolysis of the latter led to formation of 1,4-dideuterobutanes IV-VI at a ratio of ~3 : 2 : 1 in an overall yield of ~75% (Scheme 1). In each experiment, unidentifiable highmolecular compounds were formed (~15%) in addition to the above products. When the reaction of styrene was performed with Et 2 Mg instead of EtMgBr, other conditions being equal, the products were magnesacyclopentanes and/or 1,4-dimagnesium derivatives I-III (ratio ~5 : 1 : 2) in an overall yield of ~60%; in this case, no high-molec...

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Section: Methodsmentioning

confidence: 99%

Section: Reaction Of 12-dienes With Etmgbr In the Presence Of Activamentioning

confidence: 99%

Section: 5-dihexylidenemagnesacyclopentane (Xxa)mentioning

confidence: 99%

“…C NMR spectrum, δ C , ppm: 11.40 (C 1 ), 14.11 (C 9 ), 18.91 t (J CD = 19.5 Hz),22.72 (C 8 ), 27.10 (C 5 ),29.51 (C 2 ),29.71 (C 6 ), 31.99 (C 7 ), 34.36 (C 4 ), 37.11 (C 3 ).…”

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Cyclomagnesation of Olefins with Ethylmagnesium Bromide in the Presence of Titanium Complexes

et al. 2005

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“…The reactions shown in this scheme were studied by the present authors in the case of α-olefins [15][16][17][18], norbornene [19], linear allenes, and acetylenes [20][21][22].…”

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confidence: 99%

Dzhemilev reaction in the synthesis of five-membered sulfur and selenium heterocycles*

D’yakonov

Ибрагимов

Халилов

et al. 2009

Chem Heterocycl Comp

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A one-pot methods were developed for the synthesis of five-membered sulfur and selenium heterocycles based on the consecutive cyclometallation of olefins, allenes, and acetylenes using alkyl and haloalkyl derivatives of Al and Mg in the presence of catalytic amounts of titanium and zirconium complexes to give the corresponding alumina-and magnesacarbocycles in situ, which, without further purification, were introduced into reaction with sulfur or selenium, leading to various tetrahydrothiophenes, thiophenes, tetrahydroselenophenes, and selenophenes.Thiophene is separated from the coking products of mineral coal or obtained by the thermal reaction of C 4 -hydrocarbons with sulfur, hydrogen sulfide, and SO 2 [1-3]. One of the most popular synthetic methods for the preparation of tetrahydrothiophenes and selenophenes is a method based on use of the Yur'ev reaction [4,5].Along with these methods, the synthesis of five-membered heterocycles by means of replacing transition metal atoms, in particular, the zirconium atom in zirconacyclopentanes, zirconacyclopentenes, and zirconacyclopentadienes by sulfur and selenium atoms, has been found feasible [6][7][8][9]. Unfortunately, this method has not found common use due to the need to employ stoichiometric amounts of the zirconacycloalkanes and the difficulty in preparing these organometallic precursors.The reactions of metallacycloalkanes, prepared in situ using nontransition metals, aluminacyclopentanes [10-12], magnesacyclopentanes [13,14], and their derivatives prepared in situ by the Dzhemilev reaction by means of the catalytic cycloalumination and cyclomagnesation of unsaturated compounds using alkyl Mg and Al derivatives by the action of catalysts derived from Ti and Zr complexes, with S 8 and Se hold promise for the synthesis of five-membered heterocycles (Scheme 1). _______ * Dedicated to Academician B. A. Trofimov of the Russian Academy of Sciences on the occasion of his seventieth jubilee.

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Catalytic cyclometalation reaction of unsaturated compounds in synthesis of magnesa- and aluminacarbocycles

Джемилев

Ибрагимов

2010

Journal of Organometallic Chemistry

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ChemInform Abstract: New Method for the Synthesis of Monoalkyl‐Substituted Cyclobutanes.

Abstract: The 1‐alkenes (I) are treated with triethylaluminum (II) in the presence of zirconocene dichloride to generate the aluminacyclopentanes (III).

Cited by 6 publications

References 0 publications

Cyclomagnesation of Olefins with Ethylmagnesium Bromide in the Presence of Titanium Complexes

Cyclomagnesation of Olefins with Ethylmagnesium Bromide in the Presence of Titanium Complexes

Dzhemilev reaction in the synthesis of five-membered sulfur and selenium heterocycles*

Catalytic cyclometalation reaction of unsaturated compounds in synthesis of magnesa- and aluminacarbocycles

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