Results 61 to 70 of about 15,429 (247)

Chemoenzymatic Synthesis of Well‐Defined α(2,8)‐ and α(2,9)‐Linked Oligosialosides

Angewandte Chemie, EarlyView.
Well‐defined α(2,8)‐ and α(2,9)‐linked oligosialic acids of different lengths can be prepared by employing recombinant bacterial polysialyltransferases in combination with chemically modified CMP‐Neu5Ac derivatives. After transfer, a sialoside is formed bearing an artificial entity, which blocks further glycosylation.
Jelle A. Fok, Keshav Kishor, Mehman I. Bunyatov, Gerlof P. Bosman, Geert‐Jan Boons   +4 more
wiley   +2 more sources

Exploring the Phe-Gly Dipeptide-Derived Piperazinone Scaffold in the Search for Antagonists of the Thrombin Receptor PAR1

Molecules, 2014
A series of Phe-Gly dipeptide-derived piperazinones containing an aromatic urea moiety and a basic amino acid has been synthesized and evaluated as inhibitors of human platelet aggregation induced by the PAR1 agonist SFLLRN and as cytotoxic agents in ...
Ángel M. Valdivielso, M. Teresa García-López, Marta Gutiérrez-Rodríguez, Rosario Herranz   +3 more
doaj   +1 more source

N–O Dual Functional Group Transposition via Energy Transfer Photocatalysis

Advanced Science, EarlyView.
N–O dual functional group transposition (dFGT) enabled by the photocatalytic energy transfer (EnT) has been developed. This methodology is applicable to both activated and unactivated alkyl derivatives for dFGT, and it also successfully extended to N–N dFGT, demonstrating its general applicability.
Lei Bao, Xueyu Wang, Yang Zhou, Beibei Zhan, Xiaheng Zhang   +4 more
wiley   +1 more source

Theoretical Study on Regioselectivity of the Diels-Alder Reaction between 1,8-Dichloroanthracene and Acrolein

Molecules, 2016
A theoretical study of the regioselectivity of the Diels-Alder reaction between 1,8-dichloroanthracene and acrolein is performed using DFT at the B3LYP/6-31G(d,p) level of theory.
Mujeeb A. Sultan, Usama Karama, Abdulrahman I. Almansour, Saied M. Soliman   +3 more
doaj   +1 more source

Predicting Flavonoid UGT Regioselectivity [PDF]

Advances in Bioinformatics, 2011
Machine learning was applied to a challenging and biologically significant protein classification problem: the prediction of avonoid UGT acceptor regioselectivity from primary sequence. Novel indices characterizing graphical models of residues were proposed and found to be widely distributed among existing amino acid indices and to cluster residues ...
Jackson, Rhydon, Knisley, Debra, McIntosh, Cecilia, Pfeiffer, Phillip   +3 more
openaire   +3 more sources

CLRe: A Synergistic Dual‐Engine Framework for One‐Step Retrosynthesis Prediction

Advanced Science, EarlyView.
CLRe uses a contrastive difficulty score to order pretrained seq2seq fine‐tuning for retrosynthesis. Reaction embeddings define the ranking score, and a cumulative easy‐to‐hard schedule expands from the easiest subset to the full training set while earlier examples remain active.
Tianhao Su, Xitao Wang, Musen Li, Guanhua Qin, Shunbo Hu, Tong‐Yi Zhang   +5 more
wiley   +1 more source

Harnessing the Reactivity of Sulfinate Salts With Cystine: An Umpolung Approach to Residue‐Specific Peptide Modification

Angewandte Chemie, EarlyView.
While cysteine is widely employed as a nucleophilic handle for peptide modification, the electrophilicity of the oxidized form, cystine, is rarely exploited. This study describes a mild, photochemical coupling of sulfinate salts with peptide disulfides.
Joshua M. Hammond, Esteban Suárez‐Picado, Lena von Sydow, Hanna Bruss, Laurent Knerr, Magnus Johansson, Anaïs Noisier, Lara R. Malins   +7 more
wiley   +2 more sources

Regioselective Substitution of BINOL

Chemical Reviews
1,1'-Bi-2-naphthol (BINOL) has been extensively used as the chirality source in the fields of molecular recognition, asymmetric synthesis, and materials science. The direct electrophilic substitution at the aromatic rings of the optically active BINOL has been developed as one of the most convenient strategies to structurally modify BINOL for diverse ...
openaire   +2 more sources

Direct Regioselective para‐Fluorination via I(I)/I(III) Catalysis

Angewandte Chemie, EarlyView.
A direct, para‐selective fluorination by I(I)/I(III) catalysis is disclosed that does not require substrate pre‐functionalization. This strategy leverages the Leonard link inherent to phenylpropanoate and phenylpropanamides to promote a spirocyclization/para‐selective sequence. The C3‐side chain maps onto a range of common drug scaffolds and allows the
Christoph Roblick, Julian D. Bendix, Timothy A. Hilton, Kathrin Bussmann, Constantin G. Daniliuc, Ryan Gilmour   +5 more
wiley   +2 more sources

Chemoselective or Regioselective?

ChemistryEurope
Over the past two decades, there has been a notable increase in the number of reactions that have been classified as chemoselective and/or regioselective. It is somewhat surprising that neither of these terms is clearly defined, as this often leads to conflicting and confusing designations and makes it challenging to report the results coherently. This
Andrej Kolarovič, Pavol Jakubec
openaire   +2 more sources