Reaction Of Zirconacyclopentadienes Research Articles

ChemInform Abstract: Carbon-Carbon Bond Formation Reaction of Zirconacyclopentadienes with Alkynes in the Presence of Ni(II)-Complexes.

Zirconacyclopentadienes, prepared from two alkynes or a diyne, reacted with the alkyl-, trimethylsilyl-, or alkoxy-substituted third alkyne as well as an alkyne with an electron-withdrawing group in the presence of a stoichiometric amount of NiBr2(PPh3)2 to give benzene derivatives in good yields. Heteroatom-containing diynes such as dipropargylbenzylamine and propargyl-homopropargylbenzylamine gave isoindoline and tetrahydroisoquinoline derivatives in good to high yields. This procedure was also used for the selective preparation of benzene derivatives from three different alkynes. The use of trimethylsilyl-substituted alkyne as the first, second or third alkyne afforded desilylated benzene derivatives. The reaction of zirconacyclopentadienes with allenes gave benzene derivatives as a mixture of two isomers.

ChemInform Abstract: Preparation of Benzocycloheptene Derivatives from Zirconacyclopentadienes.

Reaction of zirconacyclopentadienes with 2-iodobenzyl halide and 2-iodobenzoyl halide afforded benzocycloheptene derivatives and benzocycloheptenone derivatives in good to high yields.

Cycloaddition of Zirconacyclopentadiene with 2-Bromoacrylate, 2-Bromoacrylaldehyde, and 3-Bromofuran-2,5-dione in the Presence of CuCl: A New Pathway for the Formation of Benzene Derivatives and Isobenzofuran-1,3-dione

Reaction of zirconacyclopentadienes with 2-bromoalkenes in the presence of CuCl afforded multisubstituted benzene derivatives. The reactions of 2-bromoacrylate and 2-bromo-3-phenylacrylaldehyde afforded penta- and hexasubstituted benzenes in good yields. The reaction of 3-bromofuran-2,5-dione with zirconacyclopentadienes gave isobenzofuran-1,3-diones in good yields.

Lewis Acid Controlled Reactions of Zirconacyclopentadienes with Isocyanates and Isothiocyanates. One‐Pot Three‐ or Four‐Component Synthesis of Multiply Substituted Iminocyclopentadienes and Butadiene‐Tethered 1,6‐Bisamides and Electrophilic Cyclization.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Lewis Acid‐Promoted Reactions of Zirconacyclopentadienes with Isocyanates. A One‐Pot Three‐Component Synthesis of Multiply‐Substituted Iminocyclopentadienes from one Isocyanate and Two Alkynes.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF.

Novel Synthetic Route to Octasubstituted Naphthalenes from Four Alkynes and One Olefin Unit via Zirconacyclopentadienes and 1,2‐Diiodo‐3,4,5,6‐tetraalkylbenzene.

1,2,3,4-Tetrasubstituted benzene derivatives were prepared by the reaction of zirconacyclopentadienes with vinyl bromide in the presence of NiCl2(PPh3)2. 1,2-Diiodo-3,4,5,6-tetraalkylbenzenes were formed by treatment of 1,2,3,4-tetraalkylbenzenes with iodine and periodic acid in the presence of a catalytic amount of sulfuric acid. Reaction of the 1,2-diiodo-3,4,5,6-tetraalkylbenzenes with zirconacyclopentadienes in the presence of a stoichiometric amount of CuCl gave sterically crowded octasubstituted naphthalenes in moderate yields.

Novel synthetic route to octasubstituted naphthalenes from four alkynes and one olefin unit via zirconacyclopentadienes and 1,2-diiodo-3,4,5,6-tetraalkylbenzene.

1,2,3,4-Tetrasubstituted benzene derivatives were prepared by the reaction of zirconacyclopentadienes with vinyl bromide in the presence of NiCl(2)(PPh(3))(2). 1,2-Diiodo-3,4,5,6-tetraalkylbenzenes were formed by treatment of 1,2,3,4-tetraalkylbenzenes with iodine and periodic acid in the presence of a catalytic amount of sulfuric acid. Reaction of the 1,2-diiodo-3,4,5,6-tetraalkylbenzenes with zirconacyclopentadienes in the presence of a stoichiometric amount of CuCl gave sterically crowded octasubstituted naphthalenes in moderate yields.

ChemInform Abstract: Reactions of Zirconacyclopentadienes with C=O, C=N, and N=N Moieties with Electron‐Withdrawing Groups: Formation of Six‐Membered Heterocycles.

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.

Reactions of zirconacyclopentadienes with C [double bond] ), C [double bond] N, and N [double bond] N moieties with electron-withdrawing groups: formation of six-membered heterocycles.

Reactions of zirconacyclopentadienes with diethyl ketomalonate gave alpha-pyrans in excellent yields in the presence of BiCl3. In the absence of BiCl3, zirconacyclopentadienes did not react with diethyl ketomalonate. Tetraphenylzirconacyclopentadiene reacted with diethyl ketomalonate in the presence of BiCl3 to give a ring-opening product, dienolic ether, in 53% yield. The structures of the alpha-pyran prepared from diethyldiphenylzirconacyclopentadiene and the ring-opening product were determined by X-ray analysis. When oximinosulfonate was added to tetraethylzirconacyclopentadiene in THF at -78 degrees C, 3,4,5,6-tetraethylpyridine-2-carbonitrile was obtained in 95% yield within 10 min. The structure of the product was confirmed by X-ray analysis. When tetraethylzirconacyclopentadiene was treated with azodicarboxylate in the presence of 2 equiv of CuCl at -78 degrees C, 1,2-dialkoxycarbonyl-3,4,5,6-tetraethyl-1,2-dihydropyridazine derivatives were obtained. The structure of one of dihydropyridazine was also confirmed by X-ray analysis.

Reaction of a double bond of zirconacyclopentadienes: formation of 1,2,3,5-tetrasubstituted benzenes via the C-C bond cleavage.

Reactions of zirconacyclopentadienes with dichlorocarbene afforded cyclopropanation products in good yields. In a similar manner, reactions of zirconacyclopentadienes with a Simmons-Smith type cyclopropanation reagent also gave vinylcyclopropanes in good yields after hydrolysis. Before hydrolysis, the formation of 1-zirconabicyclo[3.1.0]hexene was observed by 13C NMR spectroscopy. The 1-zirconabicyclo[3.1.0]hexene deriatives reacted with CO to produce 1,2,3,5-tetrasubstituted benzene derivatives in good yields via the C-C bond cleavage of the cyclopropane rings. This is in sharp contrast to the formation of usual 1,2,3,4-tetrasubstituted benzene derivatives from zirconacyclopentadienes.

Reactions of Zirconacyclopentadienes with Nitrosobenzene. Characterization of Zirconacycle Intermediates and Formation of N-Phenylpyrroles

Nitrosobenzene inserts into the Zr−C bond of zirconacyclopentadienes to give seven-membered zirconacyclic rings. The resulting insertion products are readily converted to N-phenylpyrroles and (in one case) a 3,3-spiroindole derivative.

Reactions of Zirconacyclopentadienes with CO and Isonitriles

Treatment of zirconacyclopentadienes with CO in the presence of NiCl2(PPh3)2 afforded cyclopentadienones. Isonitriles reacted with zirconacyclopentadienes in the absence or in the presence of NiCl2(PPh3)2, and successive treatment of the mixture with CuCl in air gave iminocyclopentadienes.

ChemInform Abstract: Formation of Cyclopentadiene Derivatives by Reaction of Zirconacyclopentadienes with 1,1-Dihalo Compounds.

Abstract Zirconacyclopentadienes reacted with benzal halides in the presence of CuCl and dimethylpropyleneurea to give pentasubstituted cyclopentadienes in moderate to good yields. Treatment of zirconacyclopentadienes with 1,1-dibromo-1-alken-3-yne and 1,1-dibromo-1,3-alkadiene afforded fulvene derivatives in good yields.

Formation of cyclopentadiene derivatives by reaction of zirconacyclopentadienes with 1,1-dihalo compounds

Zirconacyclopentadienes reacted with benzal halides in the presence of CuCl and dimethylpropyleneurea to give pentasubstituted cyclopentadienes in moderate to good yields. Treatment of zirconacyclopentadienes with 1,1-dibromo-1-alken-3-yne and 1,1-dibromo-1,3-alkadiene afforded fulvene derivatives in good yields.

Preparation of benzocycloheptene derivatives from zirconacyclopentadienes

[formula: see text] Reaction of zirconacyclopentadienes with 2-iodobenzyl halide and 2-iodobenzoyl halide afforded benzocycloheptene derivatives and benzocycloheptenone derivatives in good to high yields.

Carbon−Carbon Bond Formation Reaction of Zirconacyclopentadienes with Alkynes in the Presence of Ni(II)-complexes

Zirconacyclopentadienes, prepared from two alkynes or a diyne, reacted with the alkyl-, trimethylsilyl-, or alkoxy-substituted third alkyne as well as an alkyne with an electron-withdrawing group in the presence of a stoichiometric amount of NiBr2(PPh3)2 to give benzene derivatives in good yields. Heteroatom-containing diynes such as dipropargylbenzylamine and propargyl-homopropargylbenzylamine gave isoindoline and tetrahydroisoquinoline derivatives in good to high yields. This procedure was also used for the selective preparation of benzene derivatives from three different alkynes. The use of trimethylsilyl-substituted alkyne as the first, second or third alkyne afforded desilylated benzene derivatives. The reaction of zirconacyclopentadienes with allenes gave benzene derivatives as a mixture of two isomers.

ChemInform Abstract: Reaction of Zirconacyclopentadienes with CO in the Presence of n‐BuLi. Selective Formation of Cyclopentenone Derivatives from Two Alkynes and CO.

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.

Reaction of Zirconacyclopentadienes with CO in the Presence of n-BuLi. Selective Formation of Cyclopentenone Derivatives from Two Alkynes and CO

Reaction of Zirconacyclopentadienes with CO in the Presence of <i>n</i>-BuLi. Selective Formation of Cyclopentenone Derivatives from Two Alkynes and CO

ChemInform Abstract: Cycloaddition Reaction of Zirconacyclopentadienes to Alkynes: Highly Selective Formation of Benzene Derivatives from Three Different Alkynes.

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.

Selective one carbon-carbon bond formation reaction of zirconacyclopentadienes with aryl iodides or alkynyl iodides

Reaction of zirconacyclopentadienes with one equiv or two equiv of aryl iodides in the presence of CuCl and DMPU afforded mono-arylated diene derivatives in high yields with high selectivities. Treatment of zirconacyclopentadienes with one equiv of 2-thienyl iodide similarly gave thienyldienes in the presence of CuCl and DMPU, whereas the reaction with two equiv of 2-thienyl iodide produced thienyl iododiene derivatives in high yields. Zirconacyclopentadienes reacted with two equiv of alkynyl iodides to give iododienynes in good yields in the presence of CuCl. This is in sharp contrast to the reaction with two equiv of alkynyl iodides in the presence of CuCl and DMPU which provides dienediynes.