1453-25-4Relevant academic research and scientific papers
Synthesis of a Biomimetic Tetracyclic Precursor of Aspochalasins and Formal Synthesis of Trichoderone A
Gayraud, Oscar,Laroche, Benjamin,Casaretto, Nicolas,Nay, Bastien
supporting information, p. 5755 - 5760 (2021/08/16)
Aspochalasins are leucine-derived cytochalasins. Their complexity is associated with a high degree of biosynthetic oxidation, herein inspiring a two-phase strategy in total synthesis. We thus describe the synthesis of a putative biomimetic tetracyclic int
Photocatalytic-controlled olefin isomerization over WO3–x using low-energy photons up to 625 nm
Sun, Xichen,Waclawik, Eric R.,Wang, Yunwei,Zhang, Jin,Zheng, Zhanfeng,Zhu, Pengqi
, p. 1641 - 1647 (2021/06/28)
WO3–x (W-1) was used to achieve controllable photoisomerization of linear olefins without substituents under 625 nm light irradiation. Thermodynamic and kinetic isomers were obtained by regulating the carbon chain length of the olefins. Terminal olefins were converted into isomerized products, and the internal olefin mixtures present in petroleum derivatives were transformed into valuable pure olefin products. Oxygen vacancies (OVs) in W-1 altered the electronic structure of W-1 to improve its light-harvesting ability, which accounted for the high activity of olefin isomerization under light irradiation up to 625 nm. Additionally, OVs on the W-1 surface generated unsaturated W5+ sites that coordinated with olefins for the efficient adsorption and activation of olefins. Mechanistic studies reveal that the in situ formation of surface π-complexes and π-allylic W intermediates originating from the coordination of coordinated unsaturated W5+ sites and olefins ensure high photocatalytic activity and selectivity of W-1 for the photocatalytic isomerization of olefins via a radical mechanism.
Substituent and Ring Size Dependence of the 4J(Me-C-C-H) Coupling Constant
Collins, M. J.,Hatton, P. M.,Sternbell, S.,Tansey, C. W.
, p. 824 - 828 (2007/10/02)
The magnitude of the 4J proton-proton coupling constant across the fragment CH3-C-C-H (a probe of the bond order between the central sp2-sp2 hybridized carbon atoms) has been found to be essentially independent of substitution on a toluene fragment and the size of the ring containing the ortho-allylic fragment.The coupling constant is sensitive to direct substitution on the ortho-allilyc fragment, especially where the substituent is placed α to methyl group.KEY WORDS - 4J proton-proton coupling constant ortho-benzylic coupling constant ring size dependence substituent dependence
CLEAVAGE OF (3-CHLORO-2-METHYLENECYCLOALKYL)PALLADIUM CHLORIDE DIMERS: FORMATION OF OLEFINS AND α-METHOXYOLEFINS
Donaldson, William A.
, p. 2901 - 2908 (2007/10/02)
The cleavage of the title compounds (7) in methanolic potassium hydroxide gives mixtures of olefins and α-methoxyolefins in good yields.The ratio of the products is dependent on the size of the carbocyclic ring.The mechanism proposed involves cleavage of 7 to the corresponding allylic chloride (8).Solvolysis of the chloride gives the α-methoxyolefin.Alternatively, oxidative addition of 8 to Pd(O) generates a new ?-allyl complex which affords the olefin product upon subsequent cleavage.
REACTIVITY OF (3-CHLORO-2-METHYLENECYCLOALKYL)PALLADIUM CHLORIDE DIMERS: PD-ALLYL CLEAVAGE, SYNTHESIS OF (+/-)-13-METHYLTRIDECANOLIDE
Donaldson, William A.,Taylor, Barbara S.
, p. 4163 - 4166 (2007/10/02)
The reactions of the title compounds under cleavage conditions affords the corresponding cycloalkenes as the major product.This methodology was used in the synthesis of 13-methyltridecanolide from cyclododecene.
1,4-CYCLOHEPTYLENE AND THE RELATED ALLYLIC DIRADICALS. THERMAL NITROGEN EXTRUSION FROM 6,7-DIAZABICYCLONON-6-ENES
Uyehara, Tadao,Takahashi, Masayuki,Kato, Tadahiro
, p. 1241 - 1244 (2007/10/02)
Thermal nitrogen extrusion of 2-methylene-6,7-diazabicyclonon-6-enes and 6,7-diazabicyclonona-2,6-dienes proceeded easily to give closure and cleavage products via the corresponding 5-methylene-1,4-cycloheptylenes and 4-cyclohepten-1,3-ylenes, respectively.
1'-(6-Hydroxyoctanoyl)nornicotine and 1'-(7-Hydroxyoctanoyl)nornicotine, Two New Alkaloids from Japanese Domestic Tobacco
Miyano, Masashi,Yasumatsu, Norio,Matsushita, Hajime,Nishida, Koh
, p. 1029 - 1033 (2007/10/02)
Two new pyridine alkaloids were isolated from an extract of air-cured Japanese domestic tobacco (Nicotiana tabacum L. cv.Ibusuki).The assigned structures of 1'-(6-hydroxyoctanoyl)nornicotine (IIb) and 1'-(7-hydroxyoctanoyl)nornicotine (IIc) were based on spectroscopic properties.In addition, the structure assignments were confirmed by synthesis.
Some studies on the solvolysis of 1-chloro-1-alkyl cycloalkanes
Ranganayakulu, K.,Vasumathi Devi, M.,Balaji Rao, R.,Rajeswari, K.
, p. 1484 - 1489 (2007/10/02)
The effect of the bulk of the sidechain on the rate of solvolysis of 1-alkyl cyclopentyl, cyclohexyl, and cycloheptyl chlorides has been studied.With the exception of the t-butyl systems, the ratio of solvolysis rates for the three ring systems falls in a given series.The slower rate of solvolysis in the six-membered ring system may be due to an extra activation energy contribution caused by the conversion of a neutral chair form to the twist boat or half chair conformation, prior to the actual solvolysis.In the case of five- and seven-membered ring systems the formation of an intermediate carbonium ion is sterically favoured (I-strain or eclipsing interaction) consistent with earlier findings.The faster rate of solvolysis of 1-t-butylcycloalkyl chlorides is likely due to a rearrangement reaction where alkyl participation enhances the rate of solvolysis.
