نتایج جستجو برای: intramolecular
تعداد نتایج: 13309 فیلتر نتایج به سال:
A Cu-catalyzed new sequence involving the Ullmann type intermolecular C-C followed by an intramolecular C-N coupling and then intramolecular aza-Michael type addition (and oxidation) in a single pot afforded various fused N-heterocyclic acetic acid derivatives as inhibitors of PDE4.
The intramolecular interactions in the lipid sphingosine have been elucidated through the investigation of the amino alcohol serinol which mimics its polar headgroup. Intricate networks of intramolecular hydrogen bonds involving the hydroxyl groups and the amino group contribute to the stabilisation of five different conformations observed in the broadband rotational spectrum.
Catalytic Asymmetric Intramolecular [4+2] Cycloaddition of In Situ Generated ortho-Quinone Methides.
Herein, we describe the first catalytic asymmetric intramolecular [4+2] cycloaddition of in situ generated ortho-quinone methides. In the presence of a confined chiral imidodiphosphoric acid catalyst, various salicylaldehydes react with dienyl alcohols to give transient ortho-quinone methide intermediates, which undergo an intramolecular [4+2] cycloaddition to provide highly functionalized fura...
The Lewis acid-mediated reactions of allene-ene compounds, derived from 3-methylcitronellal or dimethyl malonate, were carried out using various Lewis acids such as ethylaluminum dichloride, diethylaluminum chloride, titanium chloride, zinc chloride etherate, or boron trifluoride etherate, affording unexpectedly intramolecular [2+2]cycloaddition products under some particular reaction condition...
An interesting silver(I)-catalyzed, one-pot intramolecular cyclization of epoxide-propargylic esters is described. A variety of 1,4-oxazine derivatives were obtained through a novel domino sequence, including three-membered ring-opening, 3,3-sigmatropic rearrangement, 6-exo-cycloisomerization and subsequent intramolecular elimination in moderate yields under mild conditions.
A series of novel chiral triazolium salts has been synthesized from readily available (1R,2R)-DPEN and found to be efficient for the enantioselective intramolecular Stetter reaction. With 10 mol% of the catalyst, the intramolecular Stetter reaction was realized in excellent yields with up to 97% ee.
Complex 2, synthesized by the reaction of {(C5H4N)(μ2-η(5):η(1)-C9H5)}Ru3(CO)9 (1) with 1,5-hexadiene, could further transform to another diruthenium complex 3via intramolecular carbometalation. The results are relevant to the mechanism of transition-metal catalyzed heteroatom-directed intramolecular C-H/olefin coupling reactions.
We report a study of dynamical intramolecular energy transfer in a realistic polyatomic molecular model system of cyclobutanone (C 4 H 6 O). It appears that for this two degree-of-freedom model system, Lyapunov relaxation does yield the same time scale as intramolecular energy exchange .
Stable crystalline phosphorus ylides are obtained in excellent yields from the 1:1:1 addition reactionbetween hydantoins or thiohydantoins and dialkyl acetylenedicarboxylates in the presence oftriphenylphosphine. These phosphoranes undergo smooth intramolecular Wittig reaction followedby an electrocyclic ring opening to produce dialkyl (E)-2-(2,5-dihydro-5,5-diaryl-2-thioxo-1H-imidazol-4-yl)fum...
The proto-oncoprotein c-Ets1 is a well-known transcription factor that belongs to the Ets family and plays a role in haematopoietic differentiation, angiogenesis, and carcinogenesis. Ets family members share a unique DNA binding domain, the Ets domain, and are known to control DNA binding activity and transcriptional activation by autoinhibition. In c-Ets1 the DNA binding domain as well as N-te...
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