Lanthanide Triflate Catalyzed Imino Diels-Alder Reactions; Convenient Syntheses of Pyridine and Quinoline Derivatives

Kobayashi, Shū; Ishitani, Haruro; Nagayama, Satoshi

doi:10.1055/s-1995-4066

Cited by 235 publications

(107 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Many kinds of lactones including lactide were copolymerized with CL by many cata-lysts. Table IV indicate the results of copolymerization with CL by yttrium catalyst at 60 • C. In the cases of 5 mM CL added with only 1 mM comonomer, polymer yields were decreased dramatically from 78.3% (entry 6) to 0 for L-lactide and γ-butyrolactone (entries 19,20) or little for lactones which carbon number are bigger than CL (entries 21-23). In the cases of δ-decanolactone (entry 22) and ω-pentadecalactone (entry 23), small amount of polymers were given.…”

Section: Copolymerization Of Other Lactones With CLmentioning

confidence: 99%

“…Recently, yttrium triflate was used to promote glycosyl fluorides as a catalyst for the preparation of pyridine and quinoline derivatives. 20,21 It was found that triflate compounds with rare earth metals such as Y, Ln or Sm were stable and are active as a Lewis acids in water. In addition, it was reported that triflate compounds were used as the catalyst for cationic polymerization of isobutyl vinyl ether and p-methoxystyrene 22,23 or radical polymerization of acrylamide 24 in water.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Polymerization of Poly(ε-caprolactone) Using Yttrium Triflate

Kunioka

Wang

Onozawa

2003

Polym J

View full text Add to dashboard Cite

ABSTRACT:The ring-opening polymerization of ε-caprolactone (CL) has been initiated by yttrium triflate (trifluoromethanesulfonate) in air using simple glass vials at 60• C without desiccation steps and stirring. The number averaged molecular weight and molecular weight distribution of the obtained poly(ε-caprolactone) (PCL) was 5000-12000 and about 1.2, respectively. It was found that this polymerization reaction of CL was activated by the addition such as little water or 2-propanol. The copolymerization activities of comonomers such as L-lactide, γ-butyrolactone, δ-octanolactone, δ-decanolactone, or ω-pentadecalactone with CL by yttrium triflate were very low at 60 • C. Direct molding method during polymerization of PCL at 40• C by yttrium triflate was developed. It was found that this direct molding PCL (M n = 2000, M w /M n = 3.07) was biodegraded very slowly in a buffer (pH 7.0) with a lipase produced by Rhizoupus arrhizus.

show abstract

Section: Copolymerization Of Other Lactones With CLmentioning

confidence: 99%

mentioning

confidence: 99%

Polymerization of Poly(ε-caprolactone) Using Yttrium Triflate

Kunioka

Wang

Onozawa

2003

Polym J

View full text Add to dashboard Cite

show abstract

“…Loss of alkene stereochemistry in the product and poor exo/endo selectivity are synonymous with this reaction. There has been a resurgence of interest in this chemistry when Kobayashi demonstrated that lanthanide triflates were efficient catalysts for effecting this transformation 2 and more recently that benzotriazoles reacted with electron rich alkenes to give the same products as those of the Povarov reaction. 3 Depending on the reaction conditions tetrahydroquinolines 3 or quinolines 4, formed by Lewis acid promoted loss of ethanol followed by aerial oxidation, were the main products of Povarov reaction.…”

Section: Introductionmentioning

confidence: 99%

Unprecedented regio and stereocontrol in Povarov reaction of benzylidene-(3-nitrophenyl)amine

Stevenson¹,

Graham²

2003

Arkivoc

View full text Add to dashboard Cite

Typically, Povarov reactions of imines derived from aromatic amines and aromatic aldehydes show poor exo/endo-stereoselectivity and to date no data is available on the regioselectivity of the cyclisation when 3-substituted imines are employed. We have demonstrated that reaction using acyclic enamides as the alkene component with 3-nitro substituted imines is completely regioselective and gave only the 5-nitro substituted tetrahydroquinoline. As a bonus the reaction also became completely exo-selective with the stereochemistry of the E-alkene preserved in the tetrahydroquinoline product.

show abstract

“…This molecule represents an important precursor in the Diels-Alder reaction, generally used as an active diene in the synthesis of carbocyclic adducts and some rare heterocyclic compounds. 4 In our research we used this molecule as an electron-rich dienophile 5 in the little explored Povarov reaction, catalyzed by phosphomolybdic acid (PMA) in MeCN to obtain the new 5-methyl-5-vinyl-isoindolo[2,1-a]quinolin-11(5H)-ones.…”

Section: Introductionmentioning

confidence: 99%