Ruthenium-catalyzed Cyclization Research Articles

Ruthenium-Catalyzed Cyclization Reactions in Pursuit of Molecules That Inhibit DXP Synthase

Ruthenium-Catalyzed Cyclization Reactions in Pursuit of Molecules That Inhibit DXP Synthase

Ru3(CO)12-Catalyzed Reaction of 1,6-Diynes, Carbon Monoxide, and Water via the Reductive Coupling of Carbon Monoxide.

We report the ruthenium-catalyzed cyclization of 1,6-diynes with two molecules of carbon monoxide and water to give a variety of catechols. This reaction likely proceeds through the intermediacy of the water-gas shift reaction to generate an yne-diol-type intermediate followed by a [4 + 2] cycloaddition with 1,6-diynes. The reaction requires no external reductants or hydride sources and provides a novel and valuable method for the synthesis of a variety of catechols.

Facile Construction of an α-(1-Cyclopentenyl)ketone Core by Ruthenium-catalyzed Hydrative Cyclization of 1,6-Allenyne: Total Synthesis of (+)-Myomontanone

Ruthenium-catalyzed hydrative cyclization of 1,6-allenyne in the presence of H2O was demonstrated. The reaction proceeded via nucleophilic attack of H2O to a ruthenacyclopentene intermediate, givin...

ChemInform Abstract: Nucleophilic Addition of Amines to Ruthenium Carbenes: ortho‐(Alkynyloxy)benzylamine Cyclizations Towards 1,3‐Benzoxazines.

A new ruthenium-catalyzed cyclization of ortho-(alkynyloxy)benzylamines to dihydro-1,3-benzoxazines is reported. The cyclization is thought to take place via the vinyl ruthenium carbene intermediates which are easily formed from [Cp*RuCl(cod)] and N2CHSiMe3. The mild reaction conditions and the efficiency of the procedure allow the easy preparation of a broad range of new 2-vinyl-2-substituted 1,3-benzoxazine derivatives. Rearrangement of an internal C(sp) in the starting material into a tetrasubstituted C(sp3) atom in the final 1,3-benzoxazine is highly remarkable.

Nucleophilic addition of amines to ruthenium carbenes: ortho-(alkynyloxy)benzylamine cyclizations towards 1,3-benzoxazines.

A new ruthenium-catalyzed cyclization of ortho-(alkynyloxy)benzylamines to dihydro-1,3-benzoxazines is reported. The cyclization is thought to take place via the vinyl ruthenium carbene intermediates which are easily formed from [Cp*RuCl(cod)] and N2 CHSiMe3 . The mild reaction conditions and the efficiency of the procedure allow the easy preparation of a broad range of new 2-vinyl-2-substituted 1,3-benzoxazine derivatives. Rearrangement of an internal C(sp) in the starting material into a tetrasubstituted C(sp(3) ) atom in the final 1,3-benzoxazine is highly remarkable.

Ruthenium-catalyzed cyclization of N-carbamoyl indolines with alkynes: an efficient route to pyrroloquinolinones.

A regioselective synthesis of substituted pyrroloquinolinones via a ruthenium-catalyzed oxidative cyclization of substituted N-carbamoyl indolines with alkynes is described. The cyclization reaction was compatible with various symmetrical and unsymmetrical alkynes including substituted propiolates. Later, we performed the aromatization of pyrroloquinolinones into indole derivatives in the presence of 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ).

Synthesis of isoindolinones via a ruthenium-catalyzed cyclization of N-substituted benzamides with allylic alcohols

N-Substituted aromatic and heteroaromatic amides reacted with substituted allylic alcohols in the presence of a ruthenium catalyst, AgSbF6 and a Cu(OAc)2·H2O oxidant, affording 3-substituted isoindolinone derivatives with diverse substituents in good to excellent yields. A possible reaction mechanism involving a five-membered ruthenacycle intermediate was proposed and strongly supported by experimental evidence.

Ruthenium-catalyzed cyclization of anilides with substituted propiolates or acrylates: an efficient route to 2-quinolinones.

A Ru-catalyzed cyclization of anilides with propiolates or acrylates affording 2-quinolinones having diverse functional groups in good to excellent yields is described. Later, 2-quinolinones were converted into 3-halo-2-quinolinones and 2-chloroquinolines. The proposed mechanism was strongly supported by experimental evidence and deuterium labeling studies.

Ruthenium-catalyzed cyclization of ketoxime acetates with DMF for synthesis of symmetrical pyridines.

A novel ruthenium-catalyzed cyclization of ketoxime carboxylates with N,N-dimethylformamide (DMF) for the synthesis of tetrasubstituted symmetrical pyridines has been developed. A methyl carbon on DMF performed as a source of a one carbon synthon. And NaHSO3 plays a role in the reaction.

ChemInform Abstract: Preparation of Substituted Pyrroles via Ru(II)‐Catalyzed Coupling of Alkynes with Enamides.

AbstractThe optimized conditions can be used in DME or water.

Ruthenium-Catalyzed Asymmetric Allylic Amidation and Radical Cyclization

Ruthenium-Catalyzed Asymmetric Allylic Amidation and Radical Cyclization

A regioselective synthesis of 1-haloisoquinolines via ruthenium-catalyzed cyclization of O-methylbenzohydroximoyl halides with alkynes

A ruthenium-catalyzed highly regioselective cyclization of substituted N-methoxy benzimidoyl halides with alkynes in the presence of CsOAc (25 mol%) to give substituted 1-halo and 1-alkoxy substituted isoquinolines in good to excellent yields is described.

ChemInform Abstract: Ruthenium‐Catalyzed Cyclizations of Enynes via a Ruthenacyclopentene Intermediate: Development of Three Novel Cyclizations Controlled by a Substituent on Alkyne of Enyne

AbstractReview: 61 refs.

Synthesis of 1,2-bisalkylidenecyclopentanes from 1,6-allenynes via stereoselective addition of nucleophiles to ruthenacyclopentenes

Ruthenium-catalyzed cyclization of 1,6-allenynes occurs via the addition of heteroatom nucleophiles to ruthenacyclopentenes, providing functionalized 1,2-bisalkylidenecyclopentanes in a highly regio- and stereoselective manner.

Ruthenium‐catalyzed cyclizations of enynes via a ruthenacyclopentene intermediate: Development of three novel cyclizations controlled by a substituent on alkyne of enyne

Three novel ruthenium-catalyzed cyclizations of enynes were developed. In each cyclization, a ruthenacyclopentene derived from enyne and Cp*RuCl(cod) is a common intermediate. When an enyne having an alkyl, an ester, or a formyl group on an alkyne was reacted with Cp*RuCl(cod) under ethylene gas, ethylene was inserted into the ruthenium-sp(2) carbon bond of ruthenacyclopentene to afford ruthenacycloheptene, and β-hydrogen elimination followed by reductive elimination occurred to give a cyclic compound having a 1,3-diene moiety. When an acyl group was placed on the alkyne, the carbonyl oxygen coordinated to the ruthenium metal of ruthenacyclopentene to produce a ruthenium carbene complex, which reacted with ethylene to give a cyclic compound having a cyclopropane ring on the substituent. On the other hand, when the substituent on the alkyne was pent-4-enyl, insertion of an alkene part into ruthenacyclopentene followed by reductive elimination gave a tricyclic compound by a ruthenium-catalyzed [2+2+2] cyclization of diene and an alkyne.

ChemInform Abstract: A New Route to Cyclopentenones via Ruthenium-Catalyzed Carbonylative Cyclization of Allylic Carbonates with Alkenes.

ChemInform Abstract: A New Route to Cyclopentenones via Ruthenium-Catalyzed Carbonylative Cyclization of Allylic Carbonates with Alkenes.

Thieme Chemistry Journal Awardees -Where Are They Now? Bicyclic Alkenes: From Cycloadditions to the Discovery of New Reactions

Recent work on synthetic applications of bicyclic al­kenes is reviewed, including synthesis of substituted bicyclic al­kenes, 1,3-dipolar cycloadditions, ruthenium-catalyzed [2+2] cycloadditions, ruthenium-catalyzed cyclizations and isomerizations, rhodium-catalyzed dimerizations, ruthenium- and rhodium-catalyzed ring-opening reactions.

Ruthenium-Catalyzed Asymmetric Dehydrative Cyclization

Ruthenium-Catalyzed Asymmetric Dehydrative Cyclization

Ruthenium(II)‐Catalyzed Cyclization of Azabenzonorbornadienes with Alkynes.

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.

Construction of Isochromenes via a Ruthenium-Catalyzed Reaction of Oxabenzonorbornenes with Propargylic Alcohols

The ruthenium-catalyzed cyclization of a propargylic alcohol with an oxabenzonorbornene in methanol leads to the creation of an isochromene framework. The proposed mechanism herein discussed for the formation of the product involves six major steps, the first four being oxidative cyclization, β-hydride elimination, hydroruthenation, followed by [2+2] cycloreversion. The ruthenium carbene formed at this stage undergoes a [1,3]-alkoxide shift that provides the observed product after reductive elimination. This process, believed to occur via a cationic ruthenium species, is in competition with two other pathways, ruthenium-catalyzed [2+2] cycloaddition and cyclopropanation. Although both [Cp*Ru(CH3CN)3]PF6 and Cp*Ru(COD)Cl are effective catalysts, the latter gives better yield and product ratio. The reaction was also found to proceed with high regioselectivity and product selectivity when unsymmetrical alkenes bearing a coordinating functional group at the bridge junction were used.