Expedient Synthesis of 1,5-Diketones by Rhodium-Catalyzed Hydroacylation Enabled by C–C Bond Cleavage
作者:Rui Guo、Guozhu Zhang
DOI:10.1021/jacs.7b05427
日期:2017.9.20
A rhodium-catalyzedintermolecularhydroacylationreaction of vinyl cyclobutanols with non-chelating aldehydes has been developed. This reaction offers a new and atom-economical approach for the selective preparation of 1,5-diketones in high yields. Experimental data suggest a sequential ring-opening, transfer hydrogenation, and hydroacylation mechanism. We propose that aldehyde decarbonylation is
A visible-light mediated ring opening reaction of alkylidenecyclopropanes for the generation of homopropargyl radicals
作者:Xiao-Yu Zhang、Chao Ning、Ben Mao、Yin Wei、Min Shi
DOI:10.1039/d1sc01889b
日期:——
Classical cyclopropylcarbinyl radical clock reactions have been widely applied to conduct mechanistic studies for probing radical processes for a long time; however, alkylidenecyclopropanes, which have a similar molecular structure to methylcyclopropanes, surprisingly have not yet attracted researcher's attention for similar ringopeningradical clock processes. In recent years, photocatalytic NHPI
Photochemistry of 1,5-hexadien-3-ones: wavelength-dependent selectivity in intramolecular enone-olefin photoadditions
作者:William G. Dauben、Jeffrey M. Cogen、George A. Ganzer、Victor Behar
DOI:10.1021/ja00015a041
日期:1991.7
The photochemistry of ten 1,5-hexadien-3-ones in methanol is studied over the wavelength range of 313-366 nm, by using monochromatic light. With the goal of understanding the unusual wavelength-dependent selectivity observed for 5-methyl-1,5-hexadien-3-one (1), quantum yield measurements, structure reactivity studies, triplet sensitization, and quenching experiments are performed. While six of the
Steric Effects on Reaction Rates - III. Application of Force-Field Calculations to Chromic Acid Oxidation of Alcohols
作者:Paul Müller、Jacky Blanc、Dieter Lenoir
DOI:10.1002/hlca.19820650410
日期:1982.6.16
The rates of oxidation with chromicacid of 15 bi- and polycyclic secondary alcohols have been measured and correlated with strain changes calculated by the MM1-program between the alcohols and the corresponding ketones. A correlation of the same quality is obtained upon representation of OH-strain by CH3-strain. The significance of the correlations with respect to the oxidation mechanism as well as
Influence of the Chemical Structure on Odor Qualities and Odor Thresholds in Homologous Series of Alka-1,5-dien-3-ones, Alk-1-en-3-ones, Alka-1,5-dien-3-ols, and Alk-1-en-3-ols
作者:Katja Lorber、Peter Schieberle、Andrea Buettner
DOI:10.1021/jf404885j
日期:2014.2.5
Odor qualities and odor thresholds in air in homologous series of synthesized alk-1-en-3-ols and alka-1,5-dien-3-ols and their corresponding ketones were evaluated by gas chromatography-olfactometry. In the series of the alk-1-en-3-ols and alk-1-en-3-ones the odor quality changed successively from pungent for the compounds with five carbon atoms via metallic, vegetable-like for the six- and seven-carbon odorants to mushroom-like for the compounds with eight and nine carbon atoms. With further increase in chain length the mushroom-like impression decreased and changed to citrus-like, soapy, or herb-like. In both series, two odor threshold minima were found for the six-carbon and also for the eight- and nine-carbon odorants, respectively. In contrast to this, the odor qualities in the series of the (Z)- and (E)-alka-1,5-dien-3-ols and their corresponding ketones did not change significantly with geranium-like, metallic odors and an increasing mushroom-like odor note with increasing chain length. The lowest thresholds were found for the eight- and nine-carbon (Z)-compounds, respectively.