104513-14-6Relevant articles and documents
FACTORS AFFECTING REGIOSLECTIVITY IN THE RHODIUM-CATALYSED HYDROFORMYLATION OF VINYL ETHERS
Lazzaroni, Raffaelo,Bertozzi, Sergio,Pocai, Paolo,Troiani, Francesco,Salvadori, Piero
, p. 371 - 376 (1985)
The rhodium catalysed hydroformylation of vinyl ethers ROCH=CH2, where R is an alkyl, a benzyl or a phenyl group, has been investigated over the 20-100 deg C temperature range in the presence of Rh4(CO)12 or 2/PPh3 (1/6) as catalytic precursors.A mixture of 2-alkoxy-(or phenoxy)propanal (the α-isomer) and 3-alkoxy-(or phenoxy)propanal (the β-isomer) is obatined in good yield.The isomeric composition of the aldehydes depends on the structure of the substrate, on the catalytic precursor employed, and on the reaction temperature.The α-isomer predomines in all the cases, its predominance being greater (i) at low temperatures, (ii)in the presence of Rh4(CO)12 as catalyst precursor, and (iii) when a phenyl group is present in the β or γ position with respect to the double bond in the substrate.Electronic factors arising from the presence in the substrate of the oxygen atom and a phenyl group are more impotrant than the steric hindrance of tghe R group in detrmining the regioselectivity of the reaction.
Linear-selective hydroformylation of vinyl ether using Rh (acac)(2,2′-bis{(di[1H-indol-1-yl]phosphanyl)oxy}-1,1′-binaphthalene) – Possible way to synthesize 1,3-propanediol
Wan, Kefeng,Zhao, Jiangui,Qin, Song,Zheng, Xueli,Fu, Haiyan,Li, Ruixiang,Chen, Hua,Yang, Jijun,Yang, Chunji
, (2020/07/24)
Three bidentate phosphoramidite ligands were synthesized, characterized, and employed in Rh-catalyzed hydroformylation of vinyl ethers. The complex Rh(acac)(2,2′-bis{(di[1H-indol-1-yl]phosphanyl)oxy}-1,1′-binaphthalene} (acac = acetylacetone) (Rh-L4) was also synthesized and characterized. Rh-L4 showed good regioselectivity for the hydroformylation of vinyl ethers under mild reaction conditions: 2 MPa of syngas, 1:1 (H2/CO) substrate/catalyst molar ratio 1000:1, and 60 °C. The linear selectivity was up to 98%, and in most cases was about 80%, with no hydrogenation product formation observed, which could be a potential way to synthesize 1,3-propanediol. A mechanism study including density functional theory computational analysis showed that both Rh–H and CO insertion steps in the hydroformylation of vinyl ether were linear-preferred in our catalyst system.
Scalable Enantioselective Synthesis of Fmoc-β2-Serine and Fmoc-β2-Threonine by an Organocatalytic Mannich Reaction
Meyer, Daniel,Marti, Roger,Seebach, Dieter
, p. 4883 - 4891 (2015/08/03)
The diastereoselective Mannich reaction of functionalized aldehydes, using a phenethylamine-derived iminium precursor, by activation with prolines and prolinol derivatives have been studied. Optimized reaction conditions have been developed, allowing for scale-up and preparation of γ-amino alcohol derivatives on multi-gram scale from β-hydroxypropanal and -butanal, with diastereoselectivites of typically >73:27 and yields of >60. After chromatographic diastereoisomer separation, hydrogenolytic debenzylation, enantiomerically pure Fmoc-β2-Ser(tBu)-OH and Fmoc-β2-Thr(tBu)-OH were thus prepared on multi-gram scale in 6 steps and with overall yields of 24 and 10, respectively, starting from commercially available starting compounds.
Influence of the reaction temperature on some acid-catalized processes of 6-hydroxy-4-oxa-alkanal derivatives and related products. Ring contraction in 5-alkoxy-1,4-dioxepanes
Espinosa, Antonio,Gallo, A. Miguel,Campos, Joaquin,Entrena, Antonio
, p. 379 - 383 (2007/10/02)
The qualitative effect of the reaction temperature on some acid-catalized processes carried out on 6-hydroxy-4-oxa-alkanal derivatives may be rationalized by means of two simultaneous or competitive pathways which involve intermediates such as 5-alkoxy-1,4-dioxepane derivatives or vinyl dioxolanes.We describe herein an acid catalyzed contraction of the 5-isopropoxy-1,4-dioxepane ring in dioxane and different alcohol interchange reactions with 5-alkoxy-1,4-dioxepanes that also occur with ring contraction when the reaction temperature is 60 deg C or higher.The transacetalization reactions between 6-hydroxy-4-oxa-hexal ethylene acetal and 6-hydroxy-4-oxa-heptanal 1,2-propylene acetal and tert-butanol, carried out at the reflux of the reacting mixtures are also described.The results obtained suggest 2-vinyl-1,3-dioxolanes as reactive intermediates.In order to prove this hypothesis the reaction between 2-vinyl-1,3-dioxolane and tert-butanol at reflux has been stuied.It leads to the same reaction products.
Catalytic Oxidation of Alk-1-enes to Aldehydes
Feringa, Ben L.
, p. 909 - 910 (2007/10/02)
Aldehydes are the major products of the catalytic oxidation of alk-1-enes with air using a catalyst that comprises (MeCN)2PdClNO2, CuCl2, and a tertiary alcohol.
