نتایج جستجو برای: cyclic ketones
تعداد نتایج: 107112 فیلتر نتایج به سال:
The ubiquitous ketone carbonyl group generally deactivates substrates toward radical-based fluorinations, especially sites closest to it. Herein, ketones are used instead to direct aliphatic fluorination using Selectfluor, catalytic benzil, and visible light. Selective β- and γ-fluorination are demonstrated on rigid mono-, di-, tri-, and tetracyclic (steroidal) substrates employing both cyclic ...
Spiro-4- thiazolidinones have been synthesized by the cyclocondensation of phthalazinyl hydrazones with cyclic ketones and substituted mercapto acetic acids. Compounds were screened for their antibacterial, antifungal and antihypertensive activity. The combined elemental analyses and spectroscopic data prove the authenticity of the synthesized compounds
The direct α-arylation of carbonyl compounds using aryl halides represents a powerful method to synthesize critical building blocks for diverse useful compounds. Numerous synthetic methods exist forge C(sp2)–C(sp3) bonds although mild and metal-free ketones remains challenging transformation. Here we report green-light-mediated from readily available via activation C(sp2)–X bond (X = I, Br, Cl)...
The combination of vanadium- and organocatalysis allows for the direct oxidative coupling of cyclic tertiary amines with non-activated ketones without the need for preformed leaving groups.
Tryptophan was shown to be able to catalyze direct aldol reactions between various cyclic ketones and aromatic aldehydes in water with high enantioselectivity.
A direct β-coupling of cyclic ketones with imines has been accomplished via the synergistic combination of photoredox catalysis and organocatalysis. Transient β-enaminyl radicals derived from ketones via enamine and oxidative photoredox catalysis readily combine with persistent α-amino radicals in a highly selective hetero radical-radical coupling. This novel pathway to γ-aminoketones is predic...
Size and shape criteria for guest binding inside the cavity of an octanuclear cubic coordination cage in water have been established using a new fluorescence displacement assay to quantify guest binding. For aliphatic cyclic ketones of increasing size (from C5 to C11), there is a linear relationship between ΔG for guest binding and the guest's surface area: the change in ΔG for binding is 0.3 k...
The catalytic hydrosilylation of highly hindered and functionalized ketones is described. The combination of inexpensive catalyst precursors, CuCl and NHC.HX (NHC = N-heterocyclic carbene), leads to a highly efficient reduction mediator for the preparation of silyl ethers from unfunctionalized and functionalized alkyl, cyclic, bicyclic, aromatic, and heteroaromatic ketones. A series of catalyst...
The direct β-coupling of cyclic ketones with aryl ketones has been achieved via the synergistic combination of photoredox catalysis and organocatalysis. Diaryl oxymethyl or aryl-alkyl oxymethyl radicals, transiently generated via single-electron reduction of ketone precursors, readily merge with β-enaminyl radical species, generated by photon-induced enamine oxidation, to produce γ-hydroxyketon...
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