Hydroformylation of cyclopentenes, novel strategy for total synthesis of carba- d -fructofuranose

Seepersaud, Mohindra; Kettunen, Mika; Abu‐Surrah, Adnan S.; Repo, Timo; Voelter, Wolfgang; Al‐Abed, Yousef

doi:10.1016/s0040-4039(02)00153-3

Cited by 15 publications

(13 citation statements)

References 22 publications

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“…Synthesis of the carbasugar using Schrock's catalyst Al-Abed et al have reported the syntheses of the highly functionalized cyclopentene derivatives, carba-D-fructofuranose (Seepersaud et al, 1999(Seepersaud et al, , 2002 and carba-D-arabinofuranose (Seepersaud et al, 2000) via RCM reaction employing Schrock's catalyst from D-arabinose. The work of Lowary et al also reported the elegant synthesis of carba-D-arabinofuranoside (Callam et al, 2000) using Schrock's catalyst from D-mannose.…”

Section: Synthesis Of the Carbasugar Using Nugent's And Jacobsen's Camentioning

confidence: 99%

Recent Advances in the Synthesis of the Carbocyclic Nucleosides as Potential Antiviral Agents

Jeong

Lee

2004

Antivir Chem Chemother

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Compared with 4'-oxonucleosides, there have been far fewer systematic structure-activity relationship studies on carbocyclic nucleosides as antiviral and antitumour agents. This is mainly because of the synthetic problems in preparing the carbasugars. However, the recent discovery of the ring-closing metathesis (RCM) (a powerful tool for the preparation of 5-membered carbasugar via C-C bond formation) has made it possible to synthesize the key carbasugars to a preparative scale. This review summarizes the asymmetric syntheses of carbasugars and carbocyclic nucleosides, using an RCM reaction as a key step. Furthermore, the review includes valuable information for designing and synthesizing novel carbocyclic nucleosides.

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Section: Synthesis Of the Carbasugar Using Nugent's And Jacobsen's Camentioning

confidence: 99%

Recent Advances in the Synthesis of the Carbocyclic Nucleosides as Potential Antiviral Agents

Jeong

Lee

2004

Antivir Chem Chemother

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“…All anticipated major and minor component spectra were reconstructed using band-target entropy minimization (BTEM) without spectral preconditioning. Beside Rh 4 (s-CO) 9 (m-CO) 3 , RC(O)Rh (CO) 4 , and Rh 6 (CO) 16 , the presence of a previously unknown complex Rh 4 (s-CO) 12 was identified [59]. The same technique has led to the reconstruction of the purecomponent spectra of RhH(CO) 4 and RhD(CO) 4 for the first time [60].…”

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confidence: 99%

“…5 quantitatively (Equation 7.4), which can be converted into the corresponding alcohols [12]. The unmodified rhodium-catalyzed hydroformylation of 2-phenylsulfonylbicyclo [2.2.1] alkenes was investigated.…”

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confidence: 99%

“…The precipitated catalysts could be reused up to six times without any decrease in activity. In situ formed polyetherphosphite/Ru 3 (CO) 12 catalyst was found to be active in hydroformylation of 1-decene in n-heptane solution at 130 C and 50 bar [20].…”

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confidence: 99%

“…It was found that the acyl rhodium tetracarbonyl intermediates easily react with ethene to form acyl rhodium tricarbonyl species RC(¼O)Rh(CO) 3 (C 2 H 4 ) [61]. Deuterioformylation of 1-phenyl-1-(n-pyridyl)-ethenes in the presence of a phosphane-modified Rh 4 (CO) 12 as catalyst precursor was carried out at 100 bar of CO : D 2 ¼ 1 : 1 and 80 C at partial substrate conversion. On basis of a direct 2 H NMR analysis of the crude reaction mixture, it was concluded that the branched alkyl rhodium intermediate is almost exclusively formed [62].…”

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Carbonylation of Alkenes and Dienes

Kégl

2008

Modern Carbonylation Methods

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In the beginning, only cobalt catalysts were utilized for hydroformylation under relatively vigorous conditions. The moderate selectivity of the generally more desired linear isomers, the substantial formation of by-products, and the low stability of the catalysts forced more appropriate catalytic systems to be developed. Using donor ligands such as phosphanes resulted in an increase in the linear selectivity. Rhodium-containing catalysts, however, permitted the use of much milder conditions in combination with suitable ligands. Other transition metals such as ruthenium, palladium, platinum, and iridium also tended to show activity for hydroformylation, albeit a vast majority of works on hydroformylation still concentrated on rhodium-containing systems. Cobalt CatalystsThe initial rate of Co 2 (CO) 8 -catalyzed cyclohexene hydroformylation, triethyl orthoformate carbonylation, and CoH(CO) 4 formation from Co 2 (CO) 8 and H 2 is reduced by the addition of dinitrogen, argon, or xenon. It is assumed that the additional gas competes with one or more reactants for a coordinatively unsaturated site responsible for their activation, thus affecting the reaction rate [1].The carbonylation reaction of propylene oxide in the presence of various [Lewis acid] þ [Co(CO) 4 ] À salts was investigated using in situ attenuated total reflection infrared (ATR-IR) spectroscopy. b-Alkoxy-acyl-cobalttetracarbonyl species were found to be key intermediates from which two reaction routes start depending on the applied Lewis acid. Labile Lewis acid-alkoxy combinations primarily favor the production of lactone products [2].The reaction of olefins (1-octene, 3,3-dimethylbutene, cyclohexene) introduced into a preequilibrated Co 2 (CO) 8 þ H 2 system was investigated by high-pressure infrared spectroscopy. Based on the observed induction period for the formation of the corresponding aldehyde, the decrease in HCo(CO) 4 concentration and increase in Co 2 (CO) 8 concentration during the induction period, the active catalytic species of the type H x Co y (CO) z was proposed [3]. Experiments with isotope mixtures of H 2 /D 2 in the gas phase during the various steps of the reaction showed that the ratio of H/D isotopes in the hydrocarbon portion of the aldehyde product correlates with the HCo(CO) 4 /DCo(CO) 4 ratio in solution, whereas the RC(¼O)H/RC(¼O)D product ratio correlates with the H 2 /D 2 in the gas phase. It was concluded that the dominant pathway for the hydrogenolysis step in this type of hydroformylation is the direct reaction of hydrogen or deuterium with the acyl complex intermediate [4].The effect of argon (280 bar) on the rate of aldehyde formation in 1-hexene hydroformylation catalyzed by Co 2 (CO) 8 at 50 C, 70 bar P(CO) and 85 bar P(H 2 ) in toluene was investigated by high-pressure FT-IR spectroscopy. The initial rate of the reaction was found to be reduced by the presence of argon. A similar effect was observed in the RhH(CO)(PPh 3 ) 3 -catalyzed cyclohexene hydroformylation reaction [5]. 162j 7 Carbonylation of Alkenes and D...

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