42540-33-0Relevant academic research and scientific papers
An Engineered Alcohol Oxidase for the Oxidation of Primary Alcohols
Heath, Rachel S.,Birmingham, William R.,Thompson, Matthew P.,Taglieber, Andreas,Daviet, Laurent,Turner, Nicholas J.
, p. 276 - 281 (2019/01/04)
Structure-guided directed evolution of choline oxidase has been carried out by using the oxidation of hexan-1-ol to hexanal as the target reaction. A six-amino-acid variant was identified with a 20-fold increased kcat compared to that of the wild-type enzyme. This variant enabled the oxidation of 10 mm hexanol to hexanal in less than 24 h with 100 % conversion. Furthermore, this variant showed a marked increase in thermostability with a corresponding increase in Tm of 20 °C. Improved solvent tolerance was demonstrated with organic solvents including ethyl acetate, heptane and cyclohexane, thereby enabling improved conversions to the aldehyde by up to 30 % above conversion for the solvent-free system. Despite the evolution of choline oxidase towards hexan-1-ol, this new variant also showed increased specific activities (by up to 100-fold) for around 50 primary aliphatic, unsaturated, branched, cyclic, benzylic and halogenated alcohols.
Efficient epoxide isomerization within a self-assembled hexameric organic capsule
Caneva, Thomas,Sperni, Laura,Strukul, Giorgio,Scarso, Alessandro
, p. 83505 - 83509 (2016/11/01)
The isomerization of epoxides to the corresponding carbonyl compounds is efficiently catalyzed by the supramolecular organic nano-capsule formed by the self-assembly of six resorcin[4]arene units. The capsule provides a combination of weak Br?nsted acidity and a suitable nano-environment that favors the metal-free isomerization reaction.
Creation of a monomeric ruthenium species on the surface of micro-size copper hydrogen phosphate: An active heterogeneous catalyst for selective aerobic oxidation of alcohols
Liu, Junhua,Wang, Fang,Sun, Kunpeng,Xu, Xianlun
, p. 2439 - 2444 (2008/09/19)
A new micro-size copper hydrogen phosphate (CHP) synthesized by the emulsion method combined with a monomeric ruthenium species was found to be a very effective catalyst for the selective oxidation of alcohols. Several kinds of alcohols were transformed into the corresponding aldehydes or ketones over the RuCHP catalyst by oxygen under very mild conditions. The results showed that the CHP material was perfect as a catalyst support due to its high ion-exchange ability and adsorption capacity.
A new method for oxidation of various alcohols to the corresponding carbonyl compounds by using n-t-butylbenzenesulfinimidoyl chloride
Matsuo, Jun-Ichi,Iida, Daisuke,Tatani, Kazuya,Mukaiyama, Teruaki
, p. 223 - 234 (2007/10/03)
Various primary and secondary alcohols were smoothly oxidized to the corresponding aldehydes and ketones by using a new oxidizing agent, N-t-butylbenzenesulfinimidoyl chloride (4a), in the coexistence of DBU or zinc oxide. The present oxidation proceeded under mild conditions via five-membered intramolecular proton-transfer of an alkyl arenesulfinimidate intermediate.
A mild and efficient oxidation of alcohols with N-tert-butylphenylsulfinimidoyl chloride in the coexistence of zinc oxide
Matsuo, Jun-Ichi,Kitagawa, Hideo,Iida, Daisuke,Mukaiyama, Teruaki
, p. 150 - 151 (2007/10/03)
Various primary and secondary alcohols bearing β-aryl, alkenyl, or alkoxy moiety were efficiently oxidized to the corresponding labile aldehydes and ketones under mild conditions with N-tert-butylphenylsulfinimidoyl chloride (1) in the coexistence of zinc oxide.
The competitive and non-competitive hydroformylation of conjugated dienes starting with tetrarhodium dodecacarbonyl. An in-situ high-pressure infrared spectroscopic study
Liu, Guowei,Garland, Marc
, p. 76 - 85 (2007/10/03)
It is well known that the liquid-phase homogeneous unmodified rhodium catalysed hydroformylation of alkenes is poisoned by the presence of trace quantities of conjugated dienes. Nevertheless, some hydroformylation of conjugated dienes is possible with unmodified rhodium, and this reaction is in general slower than alkene hydroformylations at comparable reaction conditions. In the present contribution, we examined (A) the catalytic behaviour of alkenes in the presence of trace conjugated diene impurities and (B) the catalytic behaviour of a variety of dienes using Rh4(CO)12 in n-hexane solvent at 293 K under 1.0-4.0 MPa CO and 0.5-2.0 MPa H2. The analytic method was in-situ high-pressure infrared spectroscopy. It was observed that (I) in the hydroformylation of poisoned alkenes, most of the rhodium reacts with the trace quantity of conjugated dienes and not the alkenes in this competitive situation and (II) the metal carbonyl spectra of the hydroformylation of a variety of dienes are very similar. The primary absorbance maxima observed in the hydroformylations of conjugated dienes occur at circa 2109, 2091, 2087, 2064, 2049, 2037, 2030, 2020, 2012, 1999, and 1990 cm-1. Given the known chemistry Of Rh4(CO)12 under syngas, and the very well documented chemistry of Rh4(CO)12 under alkene hydroformylation conditions, the lack of bridging carbonyls in the present experiments strongly suggested that the new infrared vibrations are due to mononuclear rhodium species. Preliminary analysis suggests the presence of at least three new species. In particular, the formation of observable η3 allyl rhodium tricarbonyl species, σ allyl rhodium tetracarbonyl species and even acyl rhodium tetracarbonyl species RCORh(CO)4 (R = alkenyl and/or formylalkyl) seems probable. Characteristic wavenumbers of 2108, 2064, 2037, 2020 and 1700 cm-1 are tentatively assigned to the latter. The reduced hydroformylation activity in the competitive hydroformylation of alkenes arises due to the much higher affinity of rhodium complexes for conjugated dienes than for alkenes under otherwise similar reaction conditions.
An Oxidatively Removable Protecting Group for Aldehydes and Ketones
McDonald, Chriss E.,Nice, Lois E.,Kennedy, Kenneth E.
, p. 57 - 60 (2007/10/02)
Aldehydes and ketones can be converted to the corresponding p-methoxyphenylethylene acetals and ketals in good to excellent yield.Deprotection can be accomplished under mild conditions to produce uniformly excellent yields of the original carbonyl compound.
Acetylenes as Potential Antarafacial Components in Concerted Reactions. Formation of Pyrroles from Thermolyses of Propargylamines, of a Dihydrofuran from a Propargylic Ether, and of an Ethylidenepyrrolidine from a β-Amino Acetylene
Viola, Alfred,Collins, John J.,Filipp, Nicholas,Locke, John S.
, p. 5067 - 5075 (2007/10/02)
A thermal cyclization of acetylenic compounds provides evidence for the ability of acetylenic links to act as antarafacial components in processes.The cyclization competes with the normally favored acetylenic retro-ene reaction.Propargylic amines, without substituents whose presence would hinder a tight cyclic transition state, yield intermediate pyrrolines whose subsequent hydrogen elimination affords pyrroles in small amounts.The same process in 2-ethynyltetrahydropyran affords 8-oxabicyclooctane in 35percent yield.A related thermal reaction of N-methyl-3-hexyn-1-amine provides a quantitative transformation to N-methyl-2-ethylidenepyrrolidine in a nominal s + 2a + 2s + 2s> Moebius process, wherein the acetylenic unit is the antarafacial component.Evidence for concertedness in these reactions is discussed.
SELECTIVE HYDROFORMYLATION OF CYCLODIENES TO CYCLOALKENECARBOXALDEHYDES USING CATALYSTS DERIVED DIRECTLY FROM Rh VAPOUR AND CYCLODIENES
Salvadori, Piero,Vitulli, Giovanni,Raffaelli, Andrea,Lazzaroni, Raffaello
, p. 351 - 356 (2007/10/02)
Cocondensation of Rh atoms with cyclodienes at liquid nitrogen temperature yields Rh complexes, thermally stable in excess of the ligand, which are good catalysts for the selective hydroformylation of cyclodienes to cycloalkenecarboxaldehydes.
