Synthesis and crossover reaction of TEMPO containing block copolymer via ROMP

• Olubummo Adekunle,
• Susanne Tanner and
• Wolfgang H. Binder

Beilstein J. Org. Chem. 2010, 6, No. 59, doi:10.3762/bjoc.6.59

• -“click”-chemistry [14][15][16][17], the crossover reaction of more complex monomers remains the crucial factor in achieving defined BCP’s with low polydispersities. In a recent example, the crossover reaction of various monomers with the Grubbs’ type catalysts G1–G3 was studied in detail via MALDI mass

Bioorthogonal metabolic glycoengineering of human larynx carcinoma (HEp-2) cells targeting sialic acid

• Arne Homann,
• Riaz-ul Qamar,
• Sevnur Serim,
• Petra Dersch and
• Jürgen Seibel

Beilstein J. Org. Chem. 2010, 6, No. 24, doi:10.3762/bjoc.6.24

• )neuraminic acid (Neu5Hex) into the cell-surface glycocalyx of a human larynx carcinoma cell line (HEp-2) and its fluorescence labelling by click chemistry. Keywords: bioorthogonal metabolic glycoengineering; click chemistry; sialic acid; Introduction The surface of eukaryotic cells is heavily covered with

Synthetic incorporation of Nile Blue into DNA using 2′-deoxyriboside substitutes: Representative comparison of (R)- and (S)-aminopropanediol as an acyclic linker

• Daniel Lachmann,
• Sina Berndl,
• Otto S. Wolfbeis and
• Hans-Achim Wagenknecht

Beilstein J. Org. Chem. 2010, 6, No. 13, doi:10.3762/bjoc.6.13

• Nile Blue chromophore was incorporated into oligonucleotides using “click” chemistry for the postsynthetic modification of oligonucleotides. These were synthesized using DNA building block 3 bearing an alkyne group and reacted with the azide 4. (R)-3-amino-1,2-propanediol was applied as the linker

• at the same time – Sharpless [16] had reported that the addition of Cu(I) led to a significant increase in the reaction rate and in regioselectivity. This type of “click” chemistry matches the requirements of bioorthogonality since both two functional groups, alkyne and azide, are typically not

• modeling helps to rationalize the experimental result which is the similarity of the optical properties between the two duplexes. Conclusion “Click” chemistry allows the postsynthetic modification of oligonucleotides that were presynthesized using the DNA building block 3 bearing an alkyne group and the

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}

• Subrata Mandal,
• Wen Tai Li,
• Yan Bai,
• Jon D. Robertus and
• Sean M. Kerwin

Beilstein J. Org. Chem. 2008, 4, No. 26, doi:10.3762/bjoc.4.26

• preparation of a series of 2-substituted 5-aminooxazolo[5,4-d]pyrimidin-7(6H)-ones and related 5-thio-oxazolo[5,4-d]pyrimidines is described, including analogs suitable for further elaboration employing “click” chemistry utilizing copper-catalyzed Huisgen 1,3-dipolar cycloadditions. Two of the compounds

• prepared were found to inhibit ricin with IC50 ca. 1–3 mM. Keywords: Annulation; Click Chemistry; Cyclization; Purine Analogs; Ricin; Introduction Oxazolo[5,4-d]pyrimidines have been reported to possess a variety of biological activities including kinase inhibition [1][2], adenosine receptor antagonism

• preparation of analogs suitable for further elaboration, for example by “click” chemistry employing copper-catalyzed Huisgen 1,3-dipolar cycloadditions [18]. Results and Discussion Our previous route [5] to 8-methyl-9-oxa-guanine (2a) involved the thermal cyclodehydration of 5-(acetylamino)-2-amino-4,6

Synthesis of new triazole- based trifluoromethyl scaffolds

• Michela Martinelli,
• Thierry Milcent,
• Sandrine Ongeri and
• Benoit Crousse

Beilstein J. Org. Chem. 2008, 4, No. 19, doi:10.3762/bjoc.4.19

• scaffolds. Keywords: copper; catalysis; fluorine; heterocycle; click chemistry; peptidomimetics; Background The 1,2,3-triazole system has widespread uses, and it has been considered as an interesting component in terms of biological activity [1][2][3][4][5]. Although the use of heterocyclic moieties in

• ]. The copper(I)-catalyzed 1,3-dipolar cycloaddition [33][34][35][36][37][38] of organic azides and alkynes (also called “click chemistry”) resulting in the formation of 1,2,3-triazoles has become an increasingly attractive area [39]. According to the literature [33][34][35][36][37][38], the Cu(I