نتایج جستجو برای: selective alkylation

تعداد نتایج: 203893  

Journal: :Nature Synthesis 2022

Enantioselective functionalization of alkenes is an attractive and straightforward method to assemble molecular complexity from readily available chemical feedstocks. Although regio- enantioselective transformations the C=C bond have been extensively studied, those allylic C–H bonds unactivated are yet be explored. Here we report a palladium-catalysed branch- alkylation that capable accommodati...

2013
Stefanie Kellner Laura Bettina Kollar Antonia Ochel Manjunath Ghate Mark Helm

Selective alkylation of RNA nucleotides is an important field of RNA biochemistry, e.g. in applications of fluorescent labeling or in structural probing experiments, yet detailed structure-function studies of labeling agents are rare. Here, bromomethylcoumarins as reactive compounds for fluorescent labeling of RNA are developed as an attractive scaffold on which electronic properties can be mod...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2003
Qibing Zhou Steven E Rokita

Selective alkylation of a chosen sequence of DNA typically relies on ligand-directed delivery of a compound that expresses an intrinsic reactivity. A significant and biologically relevant enhancement in specificity is theoretically possible if such an intrinsic reactivity could be replaced by a latent activity induced solely by the target of interest, but examples of this are rare and not easil...

2009
Cédric KEPKA Maël PENHOAT Didier BARBRY

Evaluation of a new proton sponge, bis-1,1,8,8-(tetramethylguanidino)naphtalene (TMGN), in substituted phenols O-alkylation by methyl iodide in DMF has been studied. Kinetic measurements were performed in N,N-dimethylformamide-d7 and followed by H NMR using stoichiometric amounts of reagents. Plot of the results shows that the reaction follows an almost perfect second order rate law. However th...

Journal: :Nucleic acids research 1992
J A Hartley J P Bingham R L Souhami

Nitrogen mustard alkylating agents react with isolated DNA in a sequence selective manner, and the substituent attached to the drug reactive group can impose a distinct sequence preference. It is not clear however to what extent the observed DNA sequence preferences are preserved in intact cells. The highly reiterated sequence of human alpha DNA has been used to determine the sites of guanine-N...

Journal: :Cancer research 1993
T J Monroe M A Mitchell

Although considerable work has focused on characterizing the bonding chemistry and sequence selective alkylation of DNA by cyclopropylpyrroloindole compounds, little is known about the molecular consequence of their N-3-adenine adducts in whole animal systems. We have utilized a transgenic mouse system, harboring a lambda phage shuttle vector, to assess the mutagenic potential of the antitumor ...

Journal: :Analytical and Bioanalytical Chemistry 2009
Lutz F. Tietze Birgit Krewer Holm Frauendorf

One of the main problems of anti-cancer therapy is an insufficient differentiation between normal and malignant cells by the known anti-proliferant agents. The antibody-directed enzyme prodrug therapy is a promising approach for a selective treatment of cancer, in which a non-toxic prodrug is enzymatically converted into a highly cytotoxic drug at the surface of malignant cells by a targeted an...

Journal: :Chemical & Pharmaceutical Bulletin 2021

Acyclic asymmetric quaternary stereocenters, which are composed of four carbon-carbon bonds, were finely constructed by utilizing a face-selective alkylation enolate intermediates derived from an Michael addition reaction chiral lithium amide with trisubstituted (E)-α,β-unsaturated esters. The present was able to employ diverse alkyl halides as electrophile afford various adducts having all-car...

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