نتایج جستجو برای: selective alkylation
تعداد نتایج: 203893 فیلتر نتایج به سال:
Precise control over the segmented flow in a microchannel reactor offers an important tool for the optimization of reaction yield and productivity. The fluidic control over the reaction was demonstrated on the selective alkylation of benzyl cyanide to the monoalkylated product in a 250 μm microchannel reactor. The conversion of benzyl cyanide increased from 39.9% to 99.7% as a result of a 97% l...
The electrochemical behavior of quinoline in anhydrous liquid ammonia was investigated by cyclic voltammetry and controlled potential coulometry. In the absence of added alkylating agent, quinoline is reduced in two steps to yield the radical anion and dianion both of which undergo further chemical reaction. The radical anion species dimerizes to form the dimeric dianion which is stable in the ...
A four-membered oxygen ring (oxetane) can be readily grafted into native peptides and proteins through site-selective bis-alkylation of cysteine residues present as disulfides under mild and biocompatible conditions. The selective installation of the oxetane graft enhances stability and activity, as demonstrated for a range of biologically relevant cyclic peptides, including somatostatin, prote...
The alkylating potential of beta-propiolactone (BPL), beta-butyrolactone (BBL), gamma-butyrolactone, and delta-valerolactone, which can be formed by the in vivo nitrosation of primary amino acids, was investigated kinetically. The nucleophile NBP, 4-(p-nitrobenzyl)pyridine, a trap for alkylating agents, was used as an alkylation substrate. The alkylation reactions were performed under mimicked ...
Novel benzofuran-2-carboxamide ligands, which are selective for sigma receptors, have been synthesized via a microwave-assisted Perkin rearrangement reaction and a modified Finkelstein halogen-exchange used to facilitate N-alkylation. The ligands synthesized are the 3-methyl-N-phenyl-N-(3-(piperidin-1-yl)propyl)benzofuran-2-carboxamides (KSCM-1, KSCM-5 and KSCM-11). The benzofuran-2-carboxamide...
Synlett 2002, No. 12, Print: 02 12 2002. Art Id.1437-2096,E;2002,0,12,1954,1965,ftx,en;A30202ST.pdf. © Georg Thieme Verlag Stuttgart · New York ISSN 0936-5214 Abstract: Two different synthetic reactions catalyzed by an iridium complex are discussed. The first is allylic alkylation and allylic amination. This reaction proceeds via a -allyl iridium intermediate. The selectivity strongly depends o...
The current article reports theoretical studies (DFT: B3LYP/6-31CG(d)) on the structure and alkylation reactions of the anions of some secondary N-nitrosocarbamates, a class of ambident nucleophiles whose chemistry has been little explored. Several anions (1–4), with an increasing size of the carbamate alkyl (aryl) group were investigated, in an attempt to establish the influence of the size of...
Iodoacetamide inactivates glycogen phosphorylase and causes it to dissociate into monomers of 92,500 molecular weight. Three -SH groups on each monomer are alkylated, but the first reacts as rapidly as do model compounds and its alkylation does not cause inactivation. The remaining two -SH groups are alkylated several hundred times slower, at rates comparable to the loss of activity. The three ...
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