Arylmagnesium Compounds Research Articles

The Kumada-Tamao-Corriu Coupling Reaction Catalyzed by Rhodium-Aluminum Bimetallic Complexes.

Rhodium-aluminum bimetallic complexes catalyze the Kumada-Tamao-Corriu (KTC) cross-coupling reaction using arylmagnesium compounds that are generated from the corresponding aryl fluorides or chlorides in situ by these catalysts. This method allows the challenging KTC coupling reaction to be carried out using aryl fluorides as nucleophiles, which affords various biaryls.

1,3-Diphosphacyclobutene Cobalt Complexes.

The synthesis and characterization of rare 1,3-diphosphacyclobutene transition-metal complexes is described. Reactions of the cobalt-hydride complex [Co(P2 C2 tBu2 )2 H] (G) with nBuLi, tBuLi, or PhLi afforded [Li(solv)x {Co(η3 -P2 C2 tBu2 HR)(η4 -P2 C2 tBu2 )}] (1: R=nBu, (solv)x =(Et2 O)2 ; 2: R=tBu, (solv)x =(thf)2 ; 3: R=Ph, (solv)x =(Et2 O)(thf)2 ), with an η3 -coordinated 1,3-diphosphacyclobutene ligand as a result of organyl-anion attack at one of the phosphorus atoms of the bis(1,3-diphosphacyclobutadiene) backbone. In contrast to the reactions with PhLi, the aryl-magnesium compounds p-tolyl magnesium chloride and p-fluorophenyl magnesium bromide deprotonate [Co(P2 C2 tBu2 )2 H] to give the magnesium salt [Mg(MeCN)6 ][Co(η4 -P2 C2 tBu2 )2 ]2 (4), which contains a bis(1,3-diphosphacyclobutadiene)-cobaltate anion. The [Co(η4 -P2 C2 tBu2 )2 ]- anions are well separated from the octahedral [Mg(MeCN)6 ]2+ cation in the molecular structure of 4. Compound 1 reacts with Me3 SiCl to give neutral [Co(η3 -P2 C2 tBu2 HnBu)(η4 -P2 C2 tBu2 SiMe3 )] (5, 52 % yield) with an SiMe3 group attached to one of the P atoms of the previously unfunctionalized backbone.

Heterogeneous catalytic 1,4-addition of arylmagnesium compounds to chalcones

Copper(II) on a 4 Å molecular sieve support catalyses the chemoselective addition of alkyl- and arylmagnesium halides to chalcones. Only the 1,4-addition products were obtained in high yields.

ChemInform Abstract: Synthesis of Polysubstituted Naphthalenes by Iron‐Catalyzed [2 + 2 + 2] Annulation of Grignard Reagents with Alkynes.

AbstractThe iron‐catalyzed annulation reaction of internal alkynes with arylmagnesium compounds proceeds by C—H bond activation at low temperature under oxidative conditions to produce polysubstituted naphthalenes.

Continuous Preparation of Arylmagnesium Reagents in Flow with Inline IR Monitoring

A newly developed microscale ReactIR flow cell was used as a convenient and versatile inline analytical tool for Grignard formation in continuous flow chemical processing. The LiCl-mediated halogen/Mg exchange reaction was used for the preparation of functionalized arylmagnesium compounds from aryl iodides or bromides. Furthermore, inline IR monitoring was used for the analysis of conversion and possible byproduct formation, as well as a potential tool for elucidation of mechanistic details. The results described herein indicate that the continuous flow systems are effective for highly exothermic reactions such as the Grignard exchange reaction due to fast mixing and efficient heat transfer.

ChemInform Abstract: An Unprecedented Coupling Reaction of Arylmagnesium Compounds with Tetrahydrofuran Providing 2-Aryltetrahydrofuran Mediated by a Iodoalkane-EtMgBr System.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The First Asymmetric Halogen/Metal‐Exchange Reaction: Desymmetrization of Alcohols with Enantiotopic Bromoarene Substituents

Desymmetrizations of the prochiral bis(bromoaryl)alcohols 1 and 4 were effected by treatment with iPr2Mg and enantiomerically pure lithium alkoxides. The resulting arylmagnesium compounds were quenched with various electrophiles. The absolute and (if relevant) relative configurations of the resulting products were determined. The best ee/yield combination was obtained for the protonolysis furnishing monobromoalcohol (R)-2 (53 % ee, 51 % yield). The latter was converted into (R)-orphenadrine, an antihistaminic and anticholinergic drug.

One-Pot Synthesis of N-Arylpyrazoles from Aryl Halides

A facile one-pot synthesis of functionalized pyrazoles from aryllithium or arylmagnesium compounds, di-tert-butylazodicarboxylate (DBAD) as hydrazine equivalent and 1,3-dicarbonyl compounds or equivalents thereof is reported affording the desired pyrazoles in good yields.

Preparation of Polyfunctional Tertiary Amines via the Electrophilic ­Amination of Arylmagnesium Compounds Using N-Chloroamines

Functionalized arylmagnesium compounds prepared via a halogen-magnesium exchange reaction using aryl iodides or bromides and i-PrMgCl·LiCl, react rapidly with benzyl-N-chloroamines at -45 °C providing polyfunctional tertiary amines in good yields. The methodology is also successfully applied to the preparation ofchiral N-chloroamines with retention ofchirality.

Preparation and Reactions of Heteroaryl Organomagnesium Compounds

Abstract The halogen/magnesium-exchange reaction has opened new perspectives in organic synthesis and has considerably extended the range of available functionalized aryl and heteroaryl magnesium compounds bearing functional groups such as ester, nitrile, iodide, imine, or even sensitive groups like nitro, hydroxy, and boronic esters. The present review summarizes the applications of these functionalized heteroaryl- and arylmagnesium compounds for the synthesis of a wide variety of regiospecifically functionalized five- and six-membered heterocycles.

Synthesis of Polyfunctional Unsaturated Amines by the Addition of Functionalized Organomagnesium Reagents to Unsaturated Imminium Ions.

AbstractFor Abstract see ChemInform Abstract in Full Text.

A New General Preparation of Polyfunctional Diarylamines by the Addition of Functionalized Arylmagnesium Compounds to Nitroarenes.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Stereoselective Cyclizations Mediated by Functionalized Organomagnesium Reagents and Catalyzed by Cobalt or Copper Salts.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Synthesis of Polyfunctional Unsaturated Amines by the Addition of Functionalized Organomagnesium Reagents to Unsaturated Imminium Ions

The reaction of propargylic and allylic aminals with tri­fluoromethanesulfonic anhydride at low temperature produces imminium salts, which react in the presence of N-methylpyrrolidinone (NMP) with functionalized arylmagnesium compounds, providing polyfunctional propargylic and allylic amines in satisfactory yields.

A new general preparation of polyfunctional diarylamines by the addition of functionalized arylmagnesium compounds to nitroarenes.

The addition of functionalized arylmagnesium halides to nitroarenes in THF (-20 degrees C, 2 h) provides, after reductive workup (FeCl(2), NaBH(4)), various polyfunctional diarylamines in 63-86% yield. Heterocyclic arylated amines can be prepared by this one-pot procedure. A mechanistic rationale of this reaction is given.

Stereoselective cyclizations mediated by functionalized organomagnesium reagents and catalyzed by cobalt or copper salts

The iodine–magnesium exchange reaction with i-PrMgCl allows a mild preparation of functionalized arylmagnesium compounds bearing a leaving group in the molecule. With the appropriate transition-metal catalyst (a copper or cobalt salt), cyclization reactions occur leading to five- or six-membered ring systems in good yields.

Preparation of polyfunctional pyridines by a palladium(0)-catalyzed cross-coupling of functionalized aryl Grignard reagents

Difunctionalized pyridines can be prepared by a Pd(0)-catalyzed cross-coupling of functionalized arylmagnesium compounds with chloro- or bromopyridines at temperatures as low as −40°C. An addition–elimination mechanism involving a palladate intermediate is proposed.

ChemInform Abstract: Simple and Efficient TiCl4‐Mediated Synthesis of Biaryls via Arylmagnesium Compounds.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Copper‐Catalyzed Conjugate Addition of Highly Functionalized Arylmagnesium Compounds to Enones.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Fe(III)-Catalyzed Cross-Coupling Between Functionalized Arylmagnesium Compounds and Alkenyl Halides

Fe(III)-Catalyzed Cross-Coupling Between Functionalized Arylmagnesium Compounds and Alkenyl Halides