Results 71 to 80 of about 8,619 (196)

Copper‐ and Silver‐Catalyzed Reactions of Active Methylene Isocyanides: Facile Access to Highly Substituted Five‐ and Six‐Membered Heterocycles

Chemistry – A European Journal, EarlyView.
This review summarizes recent advances in copper‐ and silver‐catalyzed reactions of active methylene isocyanides for the synthesis of highly substituted five‐ and six‐membered heterocycles. Emphasis is placed on [3+n] cycloadditions, annulations, and asymmetric strategies, highlighting current limitations and future opportunities in heterocycle ...
Jimil George, Kyungsoo Oh
wiley   +1 more source

Synthesis of 2-substituted 9-oxa-guanines {5-aminooxazolo[5,4-d]pyrimidin-7(6H)-ones} and 9-oxa-2-thio-xanthines {5-mercaptooxazolo[5,4-d]pyrimidin-7(6H)-ones}

Beilstein Journal of Organic Chemistry, 2008
Oxazolo[5,4-d]pyrimidines can be considered as 9-oxa-purine analogs of naturally occurring nucleic acid bases. Interest in this ring system has increased due to recent reports of biologically active derivatives.
Subrata Mandal, Wen Tai Li, Yan Bai, Jon D. Robertus, Sean M. Kerwin   +4 more
doaj   +1 more source

X=Y–ZH compounds as potential 1,3-dipoles. Part 64: Synthesis of highly substituted conformationally restricted and spiro nitropyrrolidines via Ag(I) catalysed azomethine ylide cycloadditions [PDF]

, 2008
1,3-Dipolar reactions of imines of both acyclic and cyclic α-amino esters with a range of nitroolefins using a combination of AgOAc or Ag2O with NEt3 are described.
Albert, Amornraksa, Ayerbe, Becker, Berger, Bourguignon, Bryce, Cecilia Orgaz de la Cierva, Colin Kilner, Crooks, Dondas, Díaz-Ortiz, Fejes, Fejes, Gentles, Grigg, Grigg, Grigg, Grigg, Grigg, Grigg, Grigg, Grigg, Grigg, H. Ali Dondas, Hill, Kabalka, Krapcho, Lee, Mohammed A.B. Sarker, Nielson, Norman, Nyerges, Nyerges, Nyerges, Nyerges, Nyerges, Pak, Peterli, Pinna, Poornachandran, Poornachandran, Poornachandran, Ram, Rang, Ronald Grigg, Sader-Bakaouni, Shorter, Song, Thurkauf, Vivanco, Yan   +51 more
core   +1 more source

A Tandem Chemical Vapor Deposition Platform for the Solvent‐Free Synthesis of Polypeptide Architectures

Chemistry – A European Journal, EarlyView.
A solvent‐free, two‐step chemical vapor polymerization enables efficient, substrate‐independent synthesis of surface‐attached polypeptide films. Initiator deposition via CVD is followed by NCA ring‐opening polymerization. Characterization confirms film formation and functionalization, allowing precise micropatterning and bioactive surface design for ...
Domenic Kratzer, Martina Plank, Meike Koenig, Tahereh Mohammadi Hafshejani, Joerg Lahann   +4 more
wiley   +1 more source

Aliphatic Poly(Carbonate)s with Acid Responsive Release Mechanisms for Micellar Anti‐Tumor Drug Delivery

Macromolecular Rapid Communications, EarlyView.
Micellar systems based on biodegradable aliphatic polycarbonates and acid‐responsive triggers enhance drug solubility, stability, and tumor‐selective release. This review covers micelles with acid‐cleavable drug linkages and those that disassemble via acid‐sensitive functionalities.
Adrian V. Hauck, Lutz Nuhn
wiley   +1 more source

The Fragmentation of 2,3-Dihydroisothiazol-3-one 1,1-Dioxide Derivatives: A Novel Cheletropic Process

CHIMIA, 1992
Adducts obtained by 1,3-dipolar cycloadditions to 2,3-dihydroisothiazol-3-one 1,1-dioxides are inclined to undergo a cheletropic process, by which the newly formed heterocyclic part undergoes aromatization, while SO2 is extruded and an ...
Kaspar F. Burri
doaj   +2 more sources

Folding of a donor–acceptor polyrotaxane by using noncovalent bonding interactions [PDF]

, 2008
Mechanically interlocked compounds, such as bistable catenanes and bistable rotaxanes, have been used to bring about actuation in nanoelectromechanical systems (NEMS) and molecular electronic devices (MEDs).
A. Z. Stieg, Appella, Beebe, Berna, Binnig, Chatterjee, Collier, Collier, D. Benitez, Estroff, Fletcher, Frechet, Harth, Hawker, J. F. Stoddart, J. K. Gimzewski, J. R. Heath, Kim, Liu, Liu, Miljanic, Sheiko, Srinivasachari, Torn  e, W. R. Dichtel, W. Zhang, Wenz   +26 more
core   +3 more sources

Structure and Mechanism of PhdC, a Prenylated‐Flavin Maturase

Proteins: Structure, Function, and Bioinformatics, EarlyView.
ABSTRACT Prenylated flavin mononucleotide (prFMN) is a modified flavin cofactor required by the UbiD family of (de)carboxylase enzymes. While the reduced prFMNH2 form is produced by the flavin prenyltransferase UbiX, the corresponding two‐electron oxidized prFMNiminium form is required to support UbiD catalysis. Thus, oxidative maturation of prFMNH2 is
Dominic R. Whittall, Henry G. Box, Karl A. P. Payne, Stephen A. Marshall, David Leys   +4 more
wiley   +1 more source

Deciphering the properties and reaction mechanism of anhydromevalonate phosphate decarboxylase, a prenylated flavin mononucleotide‐dependent enzyme in the archaeal mevalonate pathway

The FEBS Journal, EarlyView.
Characterization of anhydromevalonate phosphate decarboxylase, the UbiD‐family decarboxylase involved in the archaeal mevalonate pathway, was conducted. The enzyme is responsible for the biosynthesis of isoprenoids, such as archaeal membrane lipids, respiratory quinones, and dolichols.
Rino Ishikawa, Natsumi Matsushima, Soma Ishimine, Honoka Nakamoto, Hajime Hayakawa, Yoko Yasuno, Tetsuro Shinada, Hiroshi Kawaide, Tomokazu Ito, Hisashi Hemmi   +9 more
wiley   +1 more source

Inverse electron-demand 1,3-dipolar cycloaddition of nitrile oxide with common nitriles leading to 3-functionalized 1,2,4-oxadiazoles [PDF]

, 2011
A carbamoyl-substituted nitrile oxide was generated upon treatment of easily available 2-methyl-4-nitro-3-isoxazolin-5(2H)-one with THF (not dried); the reaction proceeded efficiently even in the absence of any special reagents and reaction conditions ...
1020, 1021, 1022, 1023, 1024, 1025, 1026, 1027, Ariga, Masahiro, Hirao, Shotaro, Ise, Yumiko, Kobiro, Kazuya, Nishiwaki, Nagatoshi, Okajima, Yoshikazu, Saigo, Kazuhiko, Sawayama, Jun   +15 more
core   +1 more source