24476-17-3Relevant academic research and scientific papers
An alkylidene carbene C-H activation approach toward the enantioselective syntheses of spirolactams: Application to the synthesis of (-)-adalinine
Annadi, Krishna,Wee, Andrew G. H.
supporting information, p. 1021 - 1038 (2016/02/19)
A method based on in situ alkylidene carbene generation-C-H insertion reaction of 5-(3-oxobutyl)pyrrolidin-2-ones and 6-(3-oxobutyl)piperidin-2-ones is developed for the enantioselective synthesis of 1-azaspiro[4,4]non-6-ene-2-ones and 6-azaspiro[4,5]dec-1-ene-7-ones. The required 5-(3-oxobutyl)pyrrolidin-2-ones and 6-(3-oxobutyl)piperidin-2-ones are prepared from the Wacker oxidation of internal alkenes typified by 5-(but-2-enyl)pyrrolidin-2-ones and 6-(but-2-enyl)piperidin-2-ones, respectively. Excellent regioselectivity (≥92:8) is realized for the Wacker oxidation, and high yields (78-89%) of the desired lactam ketones are obtained. The results from further investigations into the Wacker oxidation suggested that the high regioselectivity of the oxidation in these lactam alkenes might be due to the participation of the lactam nitrogen via intramolecular coordination to Pd(II) during the reaction. Studies on alkylidene carbene generation-C-H insertion reaction of the lactam ketones revealed that the reaction efficiency is sensitive to the reaction temperature and the amount of lithio(trimethylsilyl)diazomethane employed, which led to the development of optimal reaction conditions for effecting alkylidene carbene generation-C-H insertion. Using the optimal reaction conditions, good to high yields (53-76%) of both γ- and δ-lactam spirocycles were obtained. The synthetic utility of the spirolactams was demonstrated by the synthesis of (-)-adalinine.
Preferential catalytic hydrogenation of aromatic compounds versus ketones with a palladium substituted polyoxometalate as pre-catalyst
Kogan, Vladimir,Aizenshtat, Zeev,Neumann, Ronny
, p. 272 - 274 (2007/10/03)
A palladium-substituted polyoxometalate having a Keggin structure, supported on γ-alumina or active carbon, was used as a catalyst precursor for catalytic hydrogenation. The catalyst system enabled fast hydrogenation of arenes at 30 bar H2 and 230°C. Most interesting was the finding that arenes could be selectively reduced in the presence of distal ketone groups under similar conditions, 30 bar H2 and 200°C. For example, 1-phenyl-2-propanone yielded 1-cyclohexyl-2-propanone with no reduction of the ketone moiety. Additionally, aromatic compounds with vicinal (conjugated) ketone moieties underwent complete hydrogenation to saturated hydrocarbons and catalytic McMurry coupling was observed for aliphatic aldehydes.
PHOTOCHEMISTRY OF N-ACYLAZOLES. VI). PHOTOREACTIVITIES OF 1-ACYL-1,2,4-TRIAZOLES AND OF 2-ACYLTETRAZOLES
Murato, Kazuo,Yatsunami, Takashi,Iwasaki, Shigeo
, p. 588 - 605 (2007/10/02)
Contrary to the findings in the photolysis of N-acylimidazoles (2) irradiation of 1-acyl-1,2,4-triazoles afforded no photo-Fries product, but instead products formed via the corresponding acyl radicals and aldehydes.Photolysis of 2-acyltetrazoles gave in part the same products as those obtained from the irradiation of the corresponding acyl-triazoles as well as 2-alkyl-1,3,4-oxadiazoles.N-Acyltetrazoles didn't give any photo-Fries product neither.
