- Synthesis of PNA oligoether conjugates
-
Several different approaches have been explored for conjugation of oligoethers to PNA with internally or N-terminal placed diaminopropionic acid residues. Single and double conjugation of 2-(2-(2-aminoethoxy)ethoxy)ethanol was obtained using carbonyldimidazole. Using a post PNA-assembly coupling procedure the building block 2-(2-(2-(benzoyloxy)ethoxy)ethoxy)acetic acid multiple attachment of 2-(2-(2- hydroxyethoxy)ethoxy)acetyl groups to both N-terminal and β-amino groups of inserted diaminopropionic acids residues was achieved. Use of a new oligoether functionalized amino acid allows inclusion of oligoether conjugates during on-line machine assisted synthesis which also allowed combination of methods for attachment of different oligoethers and co-conjugation of neocuproine as well as conjugation of an aminosugar.
- Ghidini, Alice,Steunenberg, Peter,Murtola, Merita,Stromberg, Roger
-
-
Read Online
- Protecting-group-free synthesis of hydroxyesters from amino alcohols
-
The synthesis of hydroxyesters from carboxylic acids and unprotected amino alcohols in both continuous flow and batch processes is reported. The formation of a transient diazonium species with a dinitrite reagent is key in this transformation. The reaction conditions are compatible with a variety of functional groups.
- Joseph-Valcin, Eve-Marline,Lebel, Hélène,Reynard, Guillaume
-
supporting information
p. 10938 - 10941
(2020/10/02)
-
- Domino Two-Step Oxidation of β-Alkoxy Alcohols to Hemiacetal Esters: Linking a Stoichiometric Step to an Organocatalytic Step with a Common Organic Oxidant
-
Primary and secondary β-alkoxy alcohols can be cleanly and efficiently oxidized into hemiacetal esters in a cascade two-step process. mCPBA serves both as a stoichiometric oxidant in the first TEMPO-catalyzed step, converting alcohols to aldehydes/ketones, and as a reagent in the second Baeyer–Villiger stoichiometric oxidation, transforming the aldehydes/ketones into hemiacetal esters. The use of an oxidant common to both steps enables the domino reaction to proceed under a single experimental setting. Longer oxidative cascade sequences are possible when this new methodology is applied to suitable substrates.
- Targel, Tom,Ramesh, Palakuri,Portnoy, Moshe
-
supporting information
p. 3017 - 3021
(2018/06/27)
-
- The in vitro transport of model thiodipeptide prodrugs designed to target the intestinal oligopeptide transporter, PepT1
-
A thiodipeptide carrier system is shown to be effective at enabling a range of covalently bound molecules, including benzyl, benzoyl and ibuprofen conjugates, to be transported via the intestinal peptide transporter PepT1, demonstrating its potential as a rational drug delivery target.
- Foley, David,Pieri, Myrtani,Pettecrew, Rachel,Price, Richard,Miles, Stephen,Lam, Ho Kam,Bailey, Patrick,Meredith, David
-
supporting information; experimental part
p. 3652 - 3656
(2009/10/23)
-
- Kinetic stabilization of an oligomeric protein by a single ligand binding event
-
Protein native state stabilization imposed by small molecule binding is an attractive strategy to prevent the misfolding and misassembly processes associated with amyloid diseases. Transthyretin (TTR) amyloidogenesis requires rate-limiting tetramer dissociation before misassembly of a partially denatured monomer ensues. Selective stabilization of the native TTR tetramer over the dissociative transition state by small molecule binding to both thyroxine binding sites raises the kinetic barrier of tetramer dissociation, preventing amyloidogenesis. Assessing the amyloidogenicity of a TTR tetramer having only one amyloidogenesis inhibitor (I) bound is challenging because the two small molecule binding constants are generally not distinct enough to allow for the exclusive formation of TTR·I in solution to the exclusion of TTR·I2 and unliganded TTR. Herein, we report a method to tether one fibril formation inhibitor to TTR by disulfide bond formation. Occupancy of only one of the two thyroxine binding sites is sufficient to inhibit tetramer dissociation in 6.0 M urea and amyloidogenesis under acidic conditions by imposing kinetic stabilization on the entire tetramer. The sufficiency of single occupancy for stabilizing the native state of TTR provides the incentive to search for compounds displaying striking negative binding cooperativity (e.g., Kd1 in nanomolar range and Kd2 in the micromolar to millimolar range), enabling lower doses of inhibitor to be employed in the clinic, mitigating potential side effects.
- Wiseman, R. Luke,Johnson, Steven M.,Kelker, Matthew S.,Foss, Ted,Wilson, Ian A.,Kelly, Jeffery W.
-
p. 5540 - 5551
(2007/10/03)
-
- Al2O3/MeSO3H (AMA) as a new reagent with high selective ability for monoesterification of diols
-
A new facile method for monoesterification of diols has been developed. A variety of diols, in particular oligoethylene glycols, were selectively monoesterified in excellent yields by reaction with aromatic and aliphatic acids in the presence of Al2O3/MeSO3H as a new reagent without use of any solvents.
- Sharghi, Hashem,Sarvari, Mona Hosseini
-
p. 3627 - 3633
(2007/10/03)
-
- Deacylation of Pyrrole and other Aromatic Ketones
-
Ethyl 4-acetyl-3,5-dimethyl-1H-pyrrole-2-carboxylate (1a) reacts rapidly with ethylene glycol in refluxing benzene with p-toluenesulfonic acid or perchloric acid as a catalyst to give ethyl 3,5-dimethyl-1H-pyrrole-2-carboxylate (3) in high yield (96 percent).Various 2- and 3-acylpyrroles can be efficiently deacylated by using this procedure.Other ketones which undergo deacylation include phenyl(2-phenylindol-3-yl)methanone (19), 1-(5-methyl-1-phenylpyrazol-4-yl)ethanone (20), and 2,4-dimethoxybenzophenone.Certain pyrrole ketones where the acyl group is flanked by two ring methyl groups are also cleaved under acidic conditions by using ethanedithiol.
- Moon, M. W.,Wade, R. A.
-
p. 2663 - 2669
(2007/10/02)
-