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Titanium(IV) isopropoxide and ethylmagnesium bromide catalyzed reaction of 2-alkynylamines with Et2Zn, followed by deuterolysis/hydrolysis and iodinolysis, affords substituted (Z)-pent-2-en-2,5-d 2-1-amines, (Z)-pent-2-en-1-amines (65–88%), and substituted (Z)-2,5-diiodopent-2-en-1-amines (55–63%). It is suggested that the reaction proceeds through the formation of cyclic organotitanium derivatives. The reaction between 1-alkynylphosphines and Et2Zn in the presence of catalytic amounts of Ti(O-iPr)4 and EtMgBr leads to trisubstituted 1-alkenylphosphine oxides with high regioselectivity and stereoselectivity.

Treatment of a solution of a 9-alkyl- or 9-aryl-2-iodopurine in dichloromethane with an ethereal solution of ethylmagnesium bromide at –5 °C generates the corresponding purin-2-ylmagnesium bromide, which reacts with aldehydes to give the corresponding 2-(hydroxyalkyl)purines in yields of 53–84%. The purin-2-yl Grignard reagents show good functional-group tolerance to ester and nitro groups, and the method permits the synthesis of the previously unknown 6-unsubstituted 2-magnesiopurines for the first time. Performing the same procedure in THF as solvent resulted either in extensive decomposition or rapid isomerization to give purin-8-ylmagnesium halides.

Treatment of a solution of 9-benzyl or 9-phenyl 6-iodopurine in dichloromethane with an ethereal solution of ethylmagnesium bromide at ambient temperature generates the corresponding purin-6-yl magnesium halides which react with aldehydes to give carbinols in 55–80% yield. Performing the same procedure with THF as solvent gave carbinols in much lower yields (≤15%).

An efficient and short approach to the total synthesis of flavoxate hydrochloride, a muscle relaxant in urinary bladder, is reported. The synthesis of flavoxate hydrochloride is accomplished from o-cresol in 5 steps with 60.3% overall yield using formylation with formaldehyde, Grignard reaction with ethylmagnesium bromide, oxidation with potassium permanganate, Kostanecki-Rabinson cyclization and esterification with thionyl chloride and piperidinoethanol as linear steps.

The ionic liquid 1-allyl-1-methylpyrrolidinium chloride was investigated as an additive to an ethylmagnesium bromide Grignard solution, for use as an advanced electrolyte in rechargeable Mg batteries. Electrochemical studies showed that the addition of the ionic liquid significantly enhanced the anodic limit of the Grignard solution by about 1 V and improved the coulombic efficiency and the kinetics of Mg deposition-stripping reactions on the negative electrode. We have also demonstrated that the Grignard solution containing the ionic liquid works well as an electrolyte in a prototype cell consisting of a Mo 6 S 8 Chevrel phase cathode and a Mg metal anode, where the original Grignard electrolyte does not function properly.

Treatment of a dichloromethane solution of 9-benzyl or 9-phenyl 6-iodopurine with ethereal ethylmagnesium bromide at ambient temperature gives the corresponding purin-6-yl magnesium halides. Addition of an aldehyde followed by heating at 100 °C in a microwave reactor yielded the corresponding carbinols in 52–81% yield.

International audience; A convenient access to 2-hydroxycyclopentenones was designed from acylcyanohydrins, byusing titanacyclopropane complexes as nucleophilic partners and an intramolecular aldolcondensation in basic conditions. The development of a one-pot procedure allows a step- andatom-economic process, and the use of Grignard reagents other than ethylmagnesium bromideprovided valuable 3,4-disubstituted 2-hydroxycyclopentenones. The utility of the hydroxy groupwas illustrated by further functionalization of the α-position using palladium-mediated cross-coupling reactions.

Simple treatment of 2-cyanobiaryls with methyllithium, ethylmagnesium bromide, butyllithium, phenyllithium, p-methylphenyllithium, etc., followed by the reaction with water and then with molecular iodine at 60 °C provided efficiently 6-methyl-, 6-ethyl-, 6-butyl-, 6-phenyl, 6-( p-methylphenyl)phenanthridines, etc., in good yields, respectively. Here, imines formed through the addition of carbanion onto the nitriles reacted with molecular iodine to form N-iodoimines smoothly, and their warming treatment induced the formation of imino radicals that smoothly cyclized onto the aryl group to give 6-alkyl- and 6-arylphenanthridines.

International audience; The diastereoselective carbocupration reaction of cyclopropenylmethyl ethers followed by addition of oxenoid leads to the formation of diastereo- and enantiomerically enriched 2,2,3,3-tetrasubstituted cyclopropanol derivatives. Ring fragmentation of the copper cyclopropanolate leads to acyclic butenal derivatives possessing enantiomerically enriched a-quaternary carbon stereocenters in a single-pot operation.

2,4,5-Trifluorobenzoic acid is a valuable synthetic intermediate with important application in pharmaceutical industry and material science. In this paper, we report a facile continuous microflow process for the synthesis of 2,4,5-trifluorobenzoic acid via the generation of an unstable aryl-Grignard reagent followed by its reaction with gaseous CO2. The microflow system is easily assembled by a simple T-micromixer, a commercial available falling film microreactor, tube microreactor and several pumps. The use of a composed T-micromixer and tube microreactor facilitates the Grignard exchange reaction of 2,4,5-trifluorobromobenzene with ethylmagnesium bromide producing 2,4,5-trifluorophenylmagnesium bromide almost in quantitative yield, and the use of the falling film microreactor enables a highly efficient gas–liquid reaction of the resultant Grignard reagent with CO2 under an atmosphere pressure, which ultimately gave the product 2,4,5-trifluorobenzoic acid in high yield with high purity after a simple and extractive workup. The influence of reaction parameters on the two steps in microreactors was discussed.

Iron-catalyzed hydromagnesiation of styrene derivatives using ethylmagnesium bromide has been investigated for the synthesis of benzylic Grignard reagents. The benzylic Grignard reagent formed in the reaction was observed directly and its conformation in solution characterized by multinuclear and variable-temperature NMR spectroscopy. The Grignard reagent could be stored for at least 2 weeks without significant loss in activity. Hydromagnesiation of styrene in tetrahydrofuran gave a mixture of monoalkyl- and dialkylmagnesium species, (1-phenylethyl)magnesium bromide (2; RMgBr) and bis(1-phenylethyl)magnesium (3; R2Mg), with the equilibrium between these species lying in favor of the dialkylmagnesium species. The thermodynamic parameters of alkyl exchange for the reaction MgBr2 + R2Mg (3) ⇌ 2RMgBr (2) were quantified, with the enthalpy and entropy of formation of 2 from MgBr2 and 3 calculated as 32 ± 7 and 0.10 ± 0.03 kJ mol–1, respectively. This methodology was applied, on a 10 mmol scale, as the key step...

The σ-aryliron complexes [5CpFe(C6H3iPr2-2,6)] (2, 5Cp = η5-C5iPr5) and [4CpFe(C6H3iPr2-2,6)] (6, 4Cp = η5-C5HiPr4) are available from the halides [5CpFe(μ-Br)]2 (1) and [4CpFe(μ-Br)]2 (4) and have been used for σ/π rearrangement reactions with trialkylaluminum compounds. Whereas trimethylaluminum can be added to 2 and 6 to form the aryltrimethylaluminate complexes [5CpFe(μ,η6:η1-C6H3iPr2-2,6)AlMe3] (3) and [4CpFe(μ,η6:η1-C6H3iPr2-2,6)AlMe3] (7) in clean σ/π rearrangement reactions, the addition of tripropylaluminum to 6 afforded a mixture containing the aryl(bromo)dipropylaluminate complex [4CpFe(μ,η6:η1-C6H3iPr2-2,6)AlBr(C3H7)2] (8). With triethylaluminum, a similar product mixture was obtained and could be separated to yield the aryl(bromo)diethylaluminate [4CpFe(μ,η6:η1-C6H3iPr2-2,6) AlBr(C2H5)2] (9), the aryltriethylaluminate [4CpFe(μ,η6:η1-C6H3iPr2-2,6)Al(C2H5)3] (10), the arene complex [4CpFe(η6-C6H4iPr2-1,3)]Br (11), and the 2-butyne complex [(4CpFe)2(μ,η2:η2-MeCCMe)] (12). The formation of 12 involves the coupling of two ethyl groups with the loss of four hydrogen atoms and could also be observed in reactions of the bromide dimer 4 or the σ aryl complex 6 with ethylmagnesium bromide. The aluminates 3, 7, 8, and 10, the arene sandwich 11, the 2-butyne complex 12, as well as the alkylcyclopentadienyliron(II) halides [5CpFe(μ-Br)]2 (1), [4CpFe(μ-Br)]2 (4), and [4CpFe(μ-I)]2 (5) have been crystallographically characterized.

The condensation of 3-arylpropynals with aryl methyl ketones in the presence of sodium hydroxide in 50% aqueous ethanol at 0°C (Claisen-Schmidt reaction) afforded up to 89% of the corresponding (E)-1,5-diarylpent-2-en-4-yn-1-ones. The E configuration of the double C=C bond and cis conformation of the enone fragment in the products in crystal and CDCl3 solution were determined by X-ray analysis and 1H NMR spectroscopy.

Reactions of 4,5-dichloroisothiazol-3-ylcarbonitrile with methylmagnesium iodide and ethylmagnesium bromide afforded the corresponding alkyl (4,5-dichloroisothiazol-3-yl) ketones. The reaction of (4,5-dichloroisothiazol-3-yl) methyl ketone with morpholine and piperidine provided 5-morpholino-(piperidino)-substituted derivatives, by the action of sodium borohydride in 2-propanol the keto group was reduced to alcoholic hydroxy group. The bromination of (4,5-dichloroisothiazol-3-yl) methyl ketone with elemental bromine gave bromomethyl (4,5-dichloroisothiazol-3-yl) ketone, whose reaction with thiourea resulted in 2-amino-4-(4,5-dichloroisothiazol-3-yl)thiazole.

Cyclomagnesiation of nitrogen-containing 1,2-dienes with Grignard compounds in the presence of activated magnesium and Cp2TiCl2 as catalyst afforded 2,5-bis(aminoalkylidene)magnesacyclopentanes in high yield.

Optically active helical poly[(S)-3-(9-alkylfluoren-9-yl)propylene oxide]s (poly-(S)-AFPOs) without additional stereogenic units were used to induce the enantioselective addition of ethylmagnesium ...

Efficient synthesis of an epothilone molecules fragment (15R)-C13-C21 was carried out from D-mannitol through its conversion into methyl 2,3-O-cyclohexylidene-D-glycerate followed by the cyclopropanation of the ester group with ethylmagnesium bromide in the presence of titanium(IV) isopropoxide and the transformation of the obtained cyclopropanol into the corresponding 2-substituted allyl bromide. The coupling of the latter catalyzed by copper with 2-methylthiazolyl-4-magnesium bromide, the shift of a double carbon-carbon bond in the product obtained into the position, conjugated with the thiazole ring, and the common transformation of the protected 1,2-diol function afforded the target compound in 15% yield.

Thirty-three different N,N-dialkyl- and N-alkyl-N-phosphorylalkyl-substituted carboxamides 9-17 were treated with unsubstituted as well as with 2-alkyl-, 2,2-dialkyl-, and 3-alkenyl-substituted ethylmagnesium bromides 6 in the presence of stoichiometric amounts of titanium tetraisopropoxide or methyltitanium triisopropoxide to furnish substituted cyclopropylamines 20-25 in 20-98% yield, depending on the substituents with no (1:1) to excellent (>25:1) diastereoselectivities. Generally higher yields (up to 98%) of the cyclopropylamines 20-28 without loss of the diastereoselectivity were obtained with methyltitanium triisopropoxide as the titanium mediator. Under these conditions, even dioxolane-protected ketones and halogen-substituted and chiral as well as achiral alkyloxyalkyl-substituted carboxamides could be converted to the correspondingly substituted cyclopropylamines with unsubstituted as well as phenyl- and a variety of alkyl-substituted ethylmagnesium bromides in addition to numerous heteroatom-containing (e.g., halogen-, trityloxy-, tetrahydropyranyloxy-substituted) Grignard reagents (62 examples altogether). The transformation of N,N-diformylalkylamines 54 with ethylmagnesium bromide in the presence of methyltitanium triisopropoxide to N,N-dicyclopropyl-N-alkylamines 55 can be brought about in up to 82% yield (6 examples). An asymmetric variant of the titanium-mediated cyclopropanation of N,N-dialkylcarboxamides has been developed by applying chiral titanium mediators generated from stoichiometric amounts of titanium tetraisopropoxide and chiral diamino or diol ligands, respectively. The most efficient chiral mediators turned out to be titanium bistaddolates that provided the corresponding cyclopropylamines with enantiomeric excesses (ee) of up to 84%. Evaluation of several silyl-based additives revealed that the reaction can also efficiently be carried out with substoichiometric amounts (down to 25 mol%) of the titanium reagent, as long as 2-aryl- or 2-ethenyl-substituted ethylmagnesium halides are used and a concomitant slight decrease in yields is accepted. The newly developed methodology was successfully applied for the preparation of analogues with cyclopropylamine moieties of known drugs and natural products such as the nicotine metabolite (S)-Cotinine as well as the insecticides Dinotefuran and Imidacloprid.

The possibility of the existence of an equilibrium in diethyl ether between ethylmagnesium bromide - prepared from 14C-labelled ethyl bromide and magnesium - and diethylmagnesium was investigated. The result was inconclusive because complete exchange of ethyl groups was found which might be attributed either to the existence of an equilibrium or to a transmetallation reaction.

The influence of oxygen on the number of individual particles in 10−3 · 10−2 molar diethyl ether solutions of ethylmagnesium bromide, diethylmagnesium, magnesium bromide and a mixture of diethylmagnesium and magnesium bromide was investigated. The ethoxide formed from the ethylmagnesium compounds is present as a trimer.

An unsymmetrically substituted 4,4′-bis(3-thienyl)biphenyl derivative of 4-(2-ethynyl-3-thienyl)-4′-(3-thienyl)biphenyl type was prepared, utilizing 4-bromo-4′-(2-iodo-3-thienyl) biphenyl as synthetic intermediate. Reaction of 4-(2-ethynyl-3-thienyl)-4′-(3-thienyl) biphenyl with ethylmagnesium bromide followed by treatment with chlorodiphenylphosphine afforded 4-[2-(2-diphenylphosphinoethynyl)-3-thienyl]-4′-(3-thienyl)biphenyl.

Four new representatives, 18, 23, 29, and 32, of the young family of dienone musks were synthesized by two general routes. The first five-step synthetic route leading to (3E)-4-(2′-alkyl-5′,5′-dimethylcyclopent-1′-enyl)but-3-en-2-onescommenced with the enolate alkylation of 2,2-dimethylcyclopentanone (13), either directly with an alkyl halide or through the Reetz tert-alkylation. Subsequent cerium(III)-mediated butynol Grignard reaction, dehydration with sulfuric acid, (E)-selective partial reduction of the triple bond with lithium aluminum hydride, and concluding pyridinium chlorochromate oxidation complemented this route. The second four-step route leading to (3E)-1-acetyl-3-alkylidene-4,4-dimethylcycloalk-1-enes commenced with the Woods–Grignard modification on the vinylogous ester 3-ethoxycyclohex-2-enone (24) employing ethylmagnesium bromide. The product 25 was then gem-6,6-dimethylated by its lithium enolate to provide 26, which was subjected to a Schlosser–Wittig reaction to introduce the 3-alkylidene substituent. Dirhodium(II) caprolactamate-catalyzed allylic oxidation with tert-butyl hydroperoxide completed the second general synthetic scheme. The four target compounds, 18, 23, 29, and 32, were designed as diseco derivatives of a carotol lead, and they all constitute musk odorants with floral-fruity side notes. A tert-butyl group at the C-6 position of the (E)-hexa-3,5-dien-2-one skeleton was found to intensify the musk odor, and (E)-4-(2′-tert-butyl-5′,5′-dimethylcyclopent-1′-enyl)but-3-en-2-one (23) was found the most intense and interesting odorant of the series, with a very uncommon undertone of beetroot and dried fruits.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

Methyl 3-bromomethylbut-3-enoate smoothly reacted with prenal, β-ionylideneacetaldehyde, benzyloxyacetaldehyde, and tributylchlorostannane in the presence of zinc and aqueous ammonium chloride in tetrahydrofuran to give the corresponding δ-hydroxy-β-methylidenecarboxylic acid esters. In the absence of ammonium chloride, satisfactory yields of the products were obtained only in the reactions with prenal and benzyloxyacetaldehyde; these reactions involved lactonization of intermediate δ-hydroxy-β-methylidenecarboxylic acid esters, and the double carbon-carbon bond migrated to the conjugated position with the lactone carbonyl group. The condensation of β-ionylideneacetaldehyde with methyl 3-bromomethylbut-3-enoate was successfully used to obtain isotretinoin. Initial methyl 3-bromomethylbut-3-enoate was synthesized in a good yield from readily accessible ethyl 3,3-diethoxypropionate via cyclopropanation with ethylmagnesium bromide in the presence of titanium tetra(isopropoxide), oxidation of the acetal moiety to ester, and cleavage of the cyclopropane ring in intermediate methyl (1-methylsulfonyloxycyclopropyl)acetate.

N-Metallation of bromoanilines with ethylmagnesium bromide followed by a reaction with trimethylchlorosilane provided N-mono and N-bis(trimethylsilyl)bromoanilines depending on the structure of substrate. The metallation of bissilylated bromoanilines with butyllithium permitted the introduction of a trimethylsilyl substituent in the aromatic ring. Previously unknown 2-bromo-N,N-bis(trimethylsilyl)aniline, 2,6-dibromo-N-trimethylsilylaniline, 2,6-dibromo-N,N-bis(trimethylsilyl)aniline, 2-bromo-6-trimethylsilylaniline, 2-bromo-6-trimethylsilyl-N,N-bis(trimethylsilyl)aniline, 2-bromo-6-trimethylsilyl-N-trimethylsilylaniline, 2,4,6-tribromo-N-trimethylsilylaniline, and 2,4,6-tribromo-N,N-bis(trimethylsilyl)aniline were prepared. The structures of the compounds obtained were established by the chromato-mass spectrometry and 1H, 13C, and 29Si NMR spectroscopy.

Interaction of titanium(IV) isopropoxide with ethylmagnesium bromide and its higher homologs leads to the generation of alkoxytitanacyclopropane species, which are able to act in the reactions with unsaturated compounds as 1,2-dicarbanionic alkylating agents. The present review is focused on the processes of intermolecular regio- and stereoselective alkylation of carboxylic esters and allylic alcohol derivatives with alkoxytitanacyclopropane reagents. The oxophilicity of the titanium atom and its tendency to form sterically crowded ate complexes are probably the main factors providing a high level of selectivity of these transformations. © 2008 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 8: 269–278; 2008: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20155

For the exploration of pharmacophoric moiety of malloapelta B (1) possessing the inhibitory activity of NF-kappaB activation, structural variation of alpha,beta-unsaturated carbonyl motif was attempted. 1 was reduced by catalytic hydrogenation, sodium borohydride, and lithium aluminumhydride. Catalytic hydrogenation with 30 psi or 15 psi of H2 gas of 1 generated 8-butyl-5,7-dimethoxy-2,2-dimethylchroman (2) and 1-(5,7-dimethoxy-2,2-dimethylchroman-8-yl)butan-1-one (3), respectively. Reduction with sodium borohydride occurred at the double bond of alpha,beta-unsaturated ketone of 1 to give 1-(5,7-dimethoxy-2,2-dimethyl-2H-chromen-8-yl)butan-1-one (4). Reduction of 1 with lithium aluminumhydride and then quenched with methanol and water produced unexpected products, 1-(5,7-dimethoxy-2,2-dimethyl-2H-chromen-8-yl)-3-methoxy-1-butene (5) and 1-(5,7-dimethoxy-2,2-dimethyl-2H-chromen-8-yl)-3-hydroxy-l-butene (6). These are formed from the isomerization of initial product 9 through the continuous conjugate carbocation intermediate 11. Addition of ethylmagnesium bromide and dimethyl malonate anion to 1 gave the conjugate adducts 7 and 8. Ethylmagesium bromide and sodium borohydride reduction unusually gave the conjugate addition due to steric congestion around carbonyl group of 1. Compound 2 exhibits the reduced inhibitory activity against NF-kappaB activation and the others do not show the activity. Therefore alpha,beta-unsaturated carbonyl group of 1 should be important for its inhibitory activity.

1,1-Dichloro-and 1-vinyl-1-chlorosilacyclanes were prepared by reactions of tetrachlorosilane or vinyltrichlorosilane with magnesium and 1,4-dibromobutane or 1,5-dibromopentane. The reactions of the products obtained with ethynylmagnesium bromide or bis(bromomagnesio)acetylene yield the corresponding ethynylsilacyclanes. Condensation of 1,1-diethynylsilacyclanes or bis(ethynylsilacyclopentyl)ethyne with an equimolar amount of ethylmagnesium bromide and methylbis(trimethylsilylethynyl)fluorosilane gave the corresponding highly unsaturated mono-and binuclear first-generation dendrimers with the cores formed by the silicon atoms incorporated in silacycloalkane fragments. The 1H, 13C, and 29Si NMR spectra of all the compounds obtained were studied. The key parameters and the chemical graph of the new dendrimers are presented.

Homoallyl and bishomoallyl alcohols with a disubstituted double bond treated with ethylmagnesium bromide in the presence of titanium(IV) isopropoxide are converted into the products of a reductive ethylation of the olefin fragment. Under similar conditions esters of β,γ-unsaturated carboxylic acids undergo a successive cyclopropanation of the ester group and reductive ethylation of the double carbon-carbon bond and yield 1-(3-ethylalkyl)cyclopropanols. The features of the observed reactions are explained in the framework of the carbometallation mechanism of the double carbon-carbon bond by the action of dialkoxytitanacyclopropane reagents.

[3559-74-8] C8H14Si (MW 138.28) InChI = 1S/C8H14Si/c1-9(2,3)8-6-4-5-7-8/h4-8H,1-3H3 InChIKey = VMFHCJPMKUTMMQ-UHFFFAOYSA-N (useful as 4π and 2π partner in a variety of cycloaddition reactions; can be deprotonated by strong bases to give the stabilized (6π-electron) (5-trimethylsilyl)cyclopentadienyl anion that reacts with electrophiles and forms stable transition metal complexes) Alternate Names: 2,4-cyclopentadien-1-yltrimethyl silane; 1-(trimethylsilyl)cyclopentadiene; 1-(trimethylsilyl)-2,4-cyclopentadiene; 5-(trimethylsilyl)cyclopentadiene; cyclopentadienyltrimethylsilane. Physical Data: bp 138–140 °C1, 2; d 0.833 g cm−31; refractive index 1.46301; 1H NMR (C6D6, 400 MHz), δ 6.8 (d, 2H), 6.6 (d, 2H), 3.3 (s, 1H), 0.2 (s, 9H) ppm3, 4; 13C NMR (CDCl3, −20 °C) δ 134.0 (d), 134.0 (d), 131.3 (d), 131.3 (d), 52.5 (s), −1.2 (q) ppm4, 5; the bond distances (determined by electron diffraction in vapor phase)6 are 1.11 ± 0.02 A (CH), 1.53 ± 0.03 A (CC), 1.40 ± 0.02 A(CC), and 1.90 ± 0.01 A (SiC). The cyclopentadienyl ring has an “envelope” conformation, the dihedral angle between planar four- and three-membered fragments of the ring being 22 ± 4°. The SiC bond makes an angle of 56 ± 4° with the plane of the bent-out “envelope flap.” Solubility: sol common organic solvents. Form Supplied in: colorless liquid; widely available. Preparative Methods: treatment of cyclopentadienylsodium (CpNa)3, 7 or lithium salt (CpLi)8 with chlorotrimethylsilane (TMSCl) leads to 5-(trimethylsilyl)-1,3-cyclopentadiene (5-TMSCPD). Cyclopentadienyl magnesium bromide (CpMgBr), prepared through exchange reaction between cyclopentadiene and ethylmagnesium bromide, react with TMSCl to afford 5-TMSCPD (45%).9 This material can also be prepared through palladium-catalyzed cyclization via intramolecular allylation of alkenyl metals (Me3Al, iBu2AlH, ZnCl2, Pd(PPh3)4; 50%).10 Purification: purified material can be prepared by vacuum distillation bp 28–29 °C, 0.2 Torr.4 Handling, Storage, and Precautions: 5-(trimethylsilyl)-1,3-cyclopentadiene should be handled only in a well-ventilated fume hood. Containers that are opened must be carefully resealed under an inert atmosphere and kept upright to prevent leakage. Moisture sensitive, recommended storage temperature −20 °C. No component of this product present at levels greater than or equal to 0.1% is identified as probable, possible, or confirmed human carcinogen by IARC (International Agency for Research on Cancer). Incompatible with strong oxidizing agents.

The reaction of 7α-acetyl-6,14-endoethano-6,7,8,14-tetrahydrothebaine with 2-(thien-2-yl)ethylmagnesium bromide was investigated. The tertiary alcohol derivative 7α-[R-1-hydroxyl-1-methyl-3-(thien-2-yl)propyl])-6,14-endoethano-6,7,8,14-tetrahydrothebaine (3) and a by-product 4 were isolated. The structure of 4 was elucidated by X-ray analysis. The Grignard reaction shows high degree of stereoselectivity according with Cram rule. The crystal structure of 4 indicates that dihydrofuran ring was opened to form a phenolic hydroxyl group and a three-membered ring structure. It maintains the main rigid structure of morphine and contains a C(6)-C(14) enthano bridge. The 1-hydroxyl-1-methyl-3-(thien-2-yl)propyl group at C(7) position adopted S-configuration.

The Grignard exchange reaction of ethylmagnesium bromide (EtMgBr) and bromopentafluorobenzene (BPFB) to give pentafluorophenylmagnesium bromide (PFPMgBr) was carried out using small- and medium-sca...

Ethoxycarbonyl groups in O -THP protected racemic diethyl malate 1 were differentiated by their reductive cyclopropanation with ethylmagnesium bromide in the presence of titanium(IV) isopropoxide and subsequent site-selective C1–C2, C2–C3 or both C1–C2 and C1–C3 ring cleavage of the cyclopropyl groups of the resulting bis-cyclopropanol 2 .

The limits of application of organomagnesium synthesis to the substitution of chlorine atoms in tetrachlorogermane with bulky alkyl groups are established. The reaction of tetrachlorogermane with 2-butylmagnesium chloride leads to the substitution of one, two, or three chlorine atoms, yielding the corresponding alkylchlorogermanes (MeEtCH)nGeCl4-n . The reaction of GeCl4 with tert-alkylmagnesium halides leads to the substitution of only one chlorine atom, yielding tert-alkyltrichlorogermanes RMe2CGeCl3 (R = Me, Et, Bu). tert-Butyltrichlorogermane reacts with ethylmagnesium bromide to give ethyl(tert-butyl)dichlorogermane. Isopropyltrichlorogermane reacts with tert-butylmagnesium chloride to give isopropyl(tert-butyl)dichlorogermane. This shows that the organomagnesium synthesis does allow linking of two bulky substituents to the germanium atom. The reaction of tert-alkyltrichlorogermanes and 2-butyltrichlorogermane in THF with ethynylmagnesium bromide, in which the hydrocarbon group is the most sterically accessible, allows substitution of all the three chlorine atoms, yielding the corresponding alkyl(triethynyl)germanes. The latter compounds react with the Grignard reagent and trimethylchlorosilane to give the corresponding alkyl(trimethylsilylethynyl)germanes.

Cyclomagnesation of terminal and cyclic olefins and 1,2-dienes with RMgHlg and R2Mg 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.

Carbamoylformamidoximes 5 are synthesized from 2-amino-2-(hydroxyimino)acetates 3 by reaction with aminomagnesium bromides 4, prepared in situ from amines 2 and ethylmagnesium bromide.

The preparation of non-symmetrical ketones by the reaction of acyl chlorides and the corresponding Grignard reagents in the presence of catalytic amounts of metal halides is described. The composition of catalyst has a great influence on the yield of the required ketone as well as on side product formation. For each catalytic system, the yield of ketone and the number of side products changes with the time of addition of the Grignard reagent. We examined the influence of both factors in our model reaction of adamantane-1-carbonyl chloride with ethylmagnesium bromide and discussed the possible mechanisms from this point of view. We have found ZnCl 2 , MnCl 2 , AlCl 3 and CuCl to be active catalytic components and developed very efficient, cheap and fast methods for the preparation of alkyl adamantyl ketones. The procedure was also tested for the synthesis of other alkyl aryl ketones.

The reaction of carboxylic esters with ethylmagnesium bromide in the presence of titanium(IV) isopropoxide, which leads to the formation of substituted cyclopropanols, was disclosed in the late 1980′s. The key organometallic intermediates in this transformation are diisopropoxytitanacyclopropane species, which act as 1,2-dicarbanionic equivalents. The intermolecular titanium-mediated cyclopropanation of carboxylic esters and subsequent transformation of the three-membered ring provides a convenient and flexible approach to the construction of the carbon skeleton of organic molecules with ketone and other functionalities. Applications of this methodology to the synthesis of natural biologically active compounds and their analogues have been published over the last fifteen years and are summarized in the present review article. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

Two novel silicon-containing acetylenic synthons, 1-[dimethyl(ethynyl)silyl]-2-[ethynyl(methyl)-(vinyl)silyl]ethyne and bis[(ethynyldimethylsilyl)ethynyl](methyl)vinylsilane, were obtained by the reaction of diethynyl(methyl)vinylsilane with ethylmagnesium bromide and ethynylfluorodimethylsilane. The reaction of magnesium derivatives of the products and diethynyl(methyl)vinylsilane with organylhalosilanes gave macrocyclic polyunsaturated silahydrocarbons containing numerous endo- and exocyclic miltiple bonds.

The Wittig olefination of ferrocene-containing chalcones leads to 1,3-dienes and their cyclodimers. The reaction of 1,3-dienes with dibromocarbene yields gem -dibromo(ferrocenylvinyl)cyclopropanes. Upon reductive dehalogenation with ethylmagnesium bromide they afford the corresponding monobromo derivatives. All the obtained compounds were characterized by 1 H and 13 C NMR, elemental analysis, and mass spectrometry. The structures of compounds 5a , b , 6g , 6h , and 7i were confirmed by X-ray diffraction analysis.