[Ir(cod)Cl](2)/DPPF or BINAP efficiently catalyzed the cycloaddition of α,ω-diynes with nitriles to give pyridines. The reaction can accommodate a very wide range nitriles. Both aliphatic and aromatic smoothly reacted Ten equivalents unactivated nitrile were enough product in high yield. Aliphatic bearing an acetal amino moiety could be used for reaction. highly regioselective unsymmetrical diyne two different internal alkyne moieties was achieved. observed regioselectivity reasonably...

The compatibility between [{IrCl(cod)}2] and ruthenium complex 1 to achieve asymmetric α-alkylative reduction of prochiral ketones with primary alcohols is an essential factor in obtaining optically active elongation the carbon skeleton good yields a high enantioselectivity. Supporting information for this article available on WWW under http://www.wiley-vch.de/contents/jc_2002/2006/z600677_s.pdf or from author. Please note: publisher not responsible content functionality any supporting...

[Ir(cod)Cl](2)/BINAP was found to be an efficient catalyst for the [2+2+2] cycloaddition of α,ω-diynes with isocyanates give 2-pyridones. A wide range can used this reaction. Both aliphatic and aromatic smoothly reacted 2-pyridones in high yields. Aliphatic were more reactive than isocyanates. For isocyanates, electronic properties substituents affected reactivity: electron-donating enhanced The reaction unsymmetrical possessing two different internal alkyne moieties regiospecific gave a...

The direct electrophilic, nucleophilic, and amphiphilic allylations of allylic alcohol by use a palladium catalyst organometallic reagents such as organoborane organozinc has been developed. phosphine–borane compound works the effective ligand for palladium-catalyzed amination alcohol. Thus, with secondary amines, reaction was completed in only 1 h, even at room temperature.

A series of chalcogenolate(Se,Te)-bridged diruthenium complexes (neutral and cationic) as well their allenylidene have been newly prepared, catalytic activities toward the propargylic substitution reactions compared with those using corresponding thiolate(S)-bridged complexes. Results both stoichiometric these together redox properties show that ease charge transfer from one Ru atom (working an electron pool) to other in (synergistic effect) may be important factors promoting a key ligand...

Novel diruthenium complexes containing chiral thiolate-bridged ligands are synthesized and characterized crystallographically. The promote enantioselective propargylic alkylation of alcohols with acetone to give the corresponding alkylated products in good yields moderate enantioselectivities (up 35% ee).

Ruthenium-catalyzed efficient preparation of the conjugated enynes can be carried out in reactions 1-cyclopropyl-2-propyn-1-ols with nitrogen- and oxygen-centered nucleophiles such as anilines water presence a catalytic amount sulfur-bridged diruthenium complexes. The use complexes catalysts realizes completely stereoselective tri- tetrasubstituted enynes, where ruthenium−allenylidene work key intermediates. direct attack on cyclopropane ring connected to an allenylidene ligand is step...

Oxidative kinetic resolution of racemic secondary alcohols by using acetone as a hydrogen acceptor in the presence catalytic amount [RuCl2(PPh3)(ferrocenyloxazolinylphosphine)] (2) proceeds effectively to recover corresponding high yields with an excellent enantioselectivity. When 1-indanol is employed alcohol, oxidation quite smoothly even 0.0025 mol % catalyst 2 give optically active good yield enantioselectivity (up 94% ee), where turnover frequency (TOF) exceeds 80 000 h-1. From...

Various alkanechalcogenolate (SR, SeR, TeR)- and benzenechalcogenolate (SPh, SePh, TePh)-bridged diruthenium complexes have been newly prepared, their catalytic activity toward the propargylation of acetone with propargylic alcohol has investigated for comparison. Ab initio molecular orbital calculations syn anti methanechalcogenolate-bridged, propane-2-selenolate-bridged, benzenethiolate-bridged carried out to explain reason favorable formation either isomer.

Abstract New chiral phosphoramidites with an amide moiety were used for iridium‐catalyzed asymmetric allylic alkylation reactions. The best results obtained a ligand bearing oxazolidinone moiety. reaction of cinnamyl acetate diethyl sodiomalonate without the use lithium chloride gave branched product 94% ee .

Double phosphinylation of propargylic alcohols with diphenylphosphine oxide in the presence a thiolate-bridged diruthenium complex as catalyst gives corresponding 2,3-bis(diphenylphosphinyl)-1-propenes high yields complete selectivity.

Abstract Nickel catalyzes the three-component coupling reaction of dimethylzinc, enyne, and carbonyls to provide tetrasubstituted allenyl alcohols. Diethylzinc diphenylzinc can participate in similar reactions corresponding alcohols reasonable yields.

4-Methylene-1,3-dioxolan-2-ones underwent oxidative addition of a Ni0 catalyst in the presence Me2 Al(OMe), followed by coupling reaction with alkynes, to form δ,ϵ-unsaturated β-ketocarboxylic acids high regio- and stereoselectivity. The proceeds [1,3] rearrangement an enol metal carbonate intermediate formal reinsertion CO2 .

Ruthenium-catalyzed allylation of aromatic compounds such as benzene, toluene, p-xylene, anisole, phenol, furans, and thiophenes with allylic alcohol derivatives gives the corresponding allylated products in good to high yields a regioselectivity. Only cationic thiolate-bridged diruthenium(III, III) complexes promote reaction. Investigation pathway reaction cinnamyl p-xylene has revealed that it proceeds via two ways: direct itself an dicinnamyl ether formed intermediate. A new IV) complex...

Die Kompatiblität von [{IrCl(cod)}2] und dem Rutheniumkomplex 1 bei der asymmetrischen α-alkylierenden Reduktion prochiraler Ketone mit primären Alkoholen ist ein wesentlicher Faktor, um optisch aktive Alkohole unter Verlängerung des Kohlenstoffgerüsts in guten Ausbeuten hoher Enantioselektivität zu erhalten.

IPrCuCl catalyzes the CO2 insertion reaction undergone by a dialkylvinylborane intermediate derived from alkynyltrialkylborate 1,2-alkyl group migration to afford α-alkyl acrylic acids with excellent regio- and stereoselectivities.

Dicationic chalcogenolate-bridged diruthenium complexes have been newly prepared by reactions of the neutral dichloride [Cp*RuCl(μ2-YR)]2 (Y = S, Se, Te; R Me, iPr) with 2 equiv silver trifluoromethanesulfonate. Reactions propargylic alcohols acetone in presence a catalytic amount these dicationic afford corresponding hexadienones moderate to good yields, sharp contrast formation γ-ketoalkynes when or monocationic are employed as catalysts.

A novel ruthenium-catalyzed reductive coupling reaction of propargylic alcohols has been found to afford the corresponding 1,5-hexadiynes in good yields with high stereoselectivity. This catalytic may proceed via hydroboration initially produced ruthenium−allenylidene intermediates pinacolborane as a key step, disclosing new reactivity allenylidene complexes.

1,1-Diaryl-1-penten-4-yn-3-ols react with diphenylphosphine oxide in the presence of a thiolate-bridged diruthenium complex as catalyst and give high yields aryl(diphenyl)phosphine products via an initial substitution followed by cyclization at produced allene intermediate. [reaction: see text]

The first regio- and stereoselective addition of 1,3-diketones to unfunctionalized internal alkynes under neutral conditions is achieved by using [Ir(cod)(2)]SbF(6) as a catalyst.

Abstract Benzyl acetate reacted with allyltrimethylsilane to give an allylation product in the presence of a catalytic amount (cyclooctadiene)rhodium(I) chloride dimer {[Rh(cod)Cl] 2 }, sodium tetrakis[3,5‐bis(trifluoromethyl)phenyl]borate (NaBARF), and triphenyl phosphite [P(OPh) 3 ] refluxing 1,2‐dichloroethane. Primary, secondary tertiary benzyl acetates could be used for reaction. Moreover, gem ‐benzyl was possible [Rh(cod)Cl] , NaBARF, P(OPh) . Monoallylation diallylation controlled by...

The combination of Pd catalyst and diethylzinc with triethylborane promotes the amphiphilic allylation aldimines 2,3-bismethylenebutane-1,4-diol derivatives to serve as bis-allylic zwitterion species form 3,4-bismethylenepiperidines via a formal [4 + 2] cycloaddition reaction. 3,4-Bismethylenepiperidine rings are applicable for synthesis isoquinoline Diels-Alder reaction followed by an oxidation DDQ.

We have found a novel method for the preparation of enantiomerically pure propargylic alkylated compounds from an achiral alcohol assisted by ruthenium complex bearing BINAP as chiral ligand. It is noteworthy that products completely opposite configurations are obtained with almost 100% ee.

Tandem reaction: The Pd-catalyzed three-component coupling reaction of an allylic alcohol, terminal alkyne, and organoborane to give (E)-1-substituted 2-alkyl-1,4-pentadienes, involving geminal allylation alkylation at the acetylenic carbon, is described. Bis-diene undergoes a similar multicomponent with acetylene organoborane, cyclization bis-π-allylpalladium, form trans-allyl pentadienyl cyclic heterocyclic compounds excellent regio- stereoselectivities (see scheme).