1193-18-6Relevant articles and documents
Two-phase synthesis of (-)-taxuyunnanine D
Wilde, Nathan C.,Isomura, Minetaka,Mendoza, Abraham,Baran, Phil S.
, p. 4909 - 4912 (2014)
The first successful effort to replicate the beginning of the Taxol oxidase phase in the laboratory is reported, culminating in the total synthesis of taxuyunnanine D, itself a natural product. Through a combination of computational modeling, reagent screening, and oxidation sequence analysis, the first three of eight C-H oxidations (at the allylic sites corresponding to C-5, C-10, and C-13) required to reach Taxol from taxadiene were accomplished. This work lays a foundation for an eventual total synthesis of Taxol capable of delivering not only the natural product but also analogs inaccessible via bioengineering.
Ruden,Litterer
, p. 2043 (1975)
Dirhodium(II) carboxylate-catalysed oxidation of allylic and benzylic alcohols
Moody, Christopher J,Palmer, Francine N
, p. 139 - 141 (2002)
Allylic and benzylic alcohols are oxidised to the corresponding carbonyl compounds using tert-butyl hydroperoxide, preferably in stoichiometric amounts, and dirhodium(II) tetraacetate as catalyst (1 mol%) in dichloromethane at ambient temperature.
A convenient one-pot synthesis of cyclohexenic primary amines
Barbot, Francis,Aidene, Mohand,Miginiac, Leone
, p. 3279 - 3289 (1998)
The reaction between Grignard reagents prepared from allylic or propargylic halides and the N-phenylsulfenimine derived from the heptane- 2,6-dione affords primary 1-alkenyl (or alkynyl)-3-methylcyclohex-2-enamines in good yields.
Role of Amine Modifiers in the Epoxidation of Allylic Alcohols with a TiO2-SiO2 Aerogel
Dusi, Marco,Mallat, Tamas,Baiker, Alfons
, p. 191 - 201 (1999)
A detailed study of the epoxidation of 3-methyl-2-cyclohexen-1-ol with tert-butylhydroperoxide revealed that the poor performance of a 20 wt% TiO2-80 wt% SiO2 aerogel was due to nonoxidative consumption of the allylic alcohol. Epoxide selectivities could be improved remarkably and acid-catalyzed side reactions suppressed by addition of small amounts of aliphatic, cycloaliphatic, or aromatic amines. The best modifier was N, N-dimethylbutylamine. Amine (1 mol%) enhanced the epoxide selectivities, related to the reactant or peroxide, from 3 to 99% and 35 to 100%, respectively. Kinetic investigations uncovered how the chemical structure and the amount of various amines influence the complex network of redox- and acid-catalyzed reactions during allylic alcohol epoxidations. The stability of amines was studied under oxidizing reaction conditions. The method of amine addition was applied also to the epoxidation of other linear and cyclic allylic alcohols and 2-hexene. The scope of this method seems to be limited to epoxidation of allylic alcohols. A model for the interaction of allylic alcohol, amine, and peroxide with the Ti active site is proposed, which can interpret the enhanced selectivity and suppressed activity in the presence of amines or other bases.
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Meinwald,Grossman
, p. 992 (1956)
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Beereboom
, (1965)
Vinylsilane-terminated cycloacylation: A general synthetic approach to four- to six-membered cyclic ketones and its regiochemical features
Kishi,Mikami,Nakai
, p. 8111 - 8118 (1991)
Intramolecular acylations of m-trimethylsilyl-m-alkenoyl chlorides (m = 4 and 5) are described which afford the expected α-alkylidenecycloalkanone and/or the unexpected cycloalkenone, depending markeldy upon the substitution pattern on the vinylsilane moiety and/or the chain length (m).
BIOTRANSFORMATION OF LIMONENE AND RELATED COMPOUNDS BY ASPERGILLUS CELLULOSAE
Noma, Yoshiaki,Yamasaki, Sumika,Asakawa, Yoshinori
, p. 2725 - 2728 (1992)
The biotransformation of (+)-, (-)- and (+/-)-limones by Aspergillus cellulosae M-77 has been investigated. (+)-Limonene was transformed mainly to (+)-isopiperperitenone, (+)-limonene-1,2-trans-diol, (+)-cis-carveol and (+)-perilly alcohol, along with the minor formation of isopiperitenol and α-terpineol, whereas (-)-limonene was transformed to (-)-perillyl alcohol, (-)-limonene-1,2-trans-diol and (+)-neodihydrocarveol as the major products, along with the minor products such as (-)-isopiperitenone.In the case of the DL-form, perillyl alcohol, limonene-trans-1,2-diol, isopiperitenone and α-terpineol were also formed. 1-Methylcyclohexene and cyclohexene were also transformed to 3-methyl-2-cyclohexenone and 2-cyclohexenone via the corresponding alcohols, respectively.Key Word Index: Aspergillus cellulosae; biotransformation; (+)-, (-)- and (+/-)-limones; isoperitenone; limonene-1,2-trans-diol; cis-carveol; α-terpineol; 1-methylcyclohexene; cyclohexene; 3-methyl-2-cyclohexenone; 2-cyclohexenone.
Liquid-phase oxidation of olefins with rare hydronium ion salt of dinuclear dioxido-vanadium(V) complexes and comparative catalytic studies with analogous copper complexes
Maurya, Abhishek,Haldar, Chanchal
, (2021/02/26)
Homogeneous liquid-phase oxidation of a number of aromatic and aliphatic olefins was examined using dinuclear anionic vanadium dioxido complexes [(VO2)2(salLH)]? (1) and [(VO2)2(NsalLH)]? (2) and dinuclear copper complexes [(CuCl)2(salLH)]? (3) and [(CuCl)2(NsalLH)]? (4) (reaction of carbohydrazide with salicylaldehyde and 4-diethylamino salicylaldehyde afforded Schiff-base ligands [salLH4] and [NsalLH4], respectively). Anionic vanadium and copper complexes 1, 2, 3, and 4 were isolated in the form of their hydronium ion salt, which is rare. The molecular structure of the hydronium ion salt of anionic dinuclear vanadium dioxido complex [(VO2)2(salLH)]? (1) was established through single-crystal X-ray analysis. The chemical and structural properties were studied using Fourier transform infrared (FT-IR), ultraviolet–visible (UV–Vis), 1H and 13C nuclear magnetic resonance (NMR), electrospray ionization mass spectrometry (ESI-MS), electron paramagnetic resonance (EPR) spectroscopy, and thermogravimetric analysis (TGA). In the presence of hydrogen peroxide, both dinuclear vanadium dioxido complexes were applied for the oxidation of a series of aromatic and aliphatic alkenes. High catalytic activity and efficiency were achieved using catalysts 1 and 2 in the oxidation of olefins. Alkenes with electron-donating groups make the oxidation processes easy. Thus, in general, aromatic olefins show better substrate conversion in comparison to the aliphatic olefins. Under optimized reaction conditions, both copper catalysts 3 and 4 fail to compete with the activity shown by their vanadium counterparts. Irrespective of olefins, metal (vanadium or copper) complexes of the ligand [salLH4] (I) show better substrate conversion(%) compared with the metal complexes of the ligand [NsalLH4] (II).
Integrated Electro-Biocatalysis for Amine Alkylation with Alcohols
Pe?afiel, Itziar,Dryfe, Robert A. W.,Turner, Nicholas J.,Greaney, Michael F.
, p. 864 - 867 (2021/01/21)
The integration of electro and bio-catalysis offers new ways of making molecules under very mild, environmentally benign conditions. We show that TEMPO mediated electro-catalytic oxidation of alcohols can be adapted to work in aqueous buffers, with minimal organic co-solvent, enabling integration with biocatalytic reductive amination using the AdRedAm enzyme. The combined process offers a new approach to amine alkylation with native alcohols, a key bond formation in the chemical economy that is currently achieved via precious metal-catalyzed hydrogen-borrowing technologies. The electrobio transformation is effective for primary and secondary alcohols undergoing coupling with allyl, propargyl, benzyl, and cyclopropyl amines, and has been adapted for use with solid-supported AdRedAm for ease of operation.
CeO2-Supported Pd(II)-on-Au Nanoparticle Catalyst for Aerobic Selective α,β-Desaturation of Carbonyl Compounds Applicable to Cyclohexanones
Jin, Xiongjie,Mizuno, Noritaka,Takei, Daisuke,Yabe, Tomohiro,Yamaguchi, Kazuya,Yatabe, Takafumi
, p. 5057 - 5063 (2020/05/27)
Direct selective desaturation of carbonyl compounds to synthesize α,β-unsaturated carbonyl compounds represents an environmentally benign alternative to classical stepwise procedures. In this study, we designed an ideal CeO2-supported Pd(II)-on-Au nanoparticle catalyst (Pd/Au/CeO2) and successfully achieved heterogeneously catalyzed selective desaturation of cyclohexanones to cyclohexenones using O2 in air as the oxidant. Besides cyclohexenones, various bioactive enones can also be synthesized from the corresponding saturated ketones under open air conditions in the presence of Pd/Au/CeO2. Preliminary mechanistic studies revealed that α-C-H bond cleavage in the substrates is the turnover-limiting step of this desaturation reaction.
