Ресурсный центр «Магнитно-резонансные методы исследования»

V.A. Rassadin, E. Nicolas, Y. Six

«Ti(OiPr)₄/nBuLi: an attractive reagent system for [2+2+2] cyclotrimerisation reactions»

Chem. Commun. 2014, Advance Article

DOI: 10.1039/C4CC02698E

A convenient method for the [2+2+2] cyclotrimerisation of alkynes using Ti(OiPr)₄/nBuLi is presented. Homotrimerisation of arylacetylenes proceeds within minutes with excellent regioselectivity. Moreover, the intermolecular construction of ABB heterotrimers can be achieved selectively from two different alkynes with similar electronic properties. The method is also suitable for the synthesis of pyridines.

16 и 18 июня прошла вторая часть семинара G-RISC “NMR as interdisciplinary tool for the study of non-covalent interactions”.
Были сделаны следующие доклады:

• Regina Islamova “Transition Metal-Catalyzed polymerisation: NMR and EPR study”;
• Roman Yakovenko «NMR study of protonation of carbonyl compounds (fluorinated enones and furanes) in Brønsted superacids»;
• Konstantin Luzyanin “Combining NMR and MS tools for study of nano clusters in solution”;
• Kirill Kulish “Zinc(II)-Mediated Generation of 5-amino-1,2,4-oxadiazoles from amidoximes and cyan amides”

J. Malinina, T.Q. Tran, A.V. Stepakov, V.V. Gurzhiy, G.L. Starova, R.R. Kostikov, A.P. Molchanov

«[3+2] Cycloaddition reactions of arylallenes with C-(N-arylcarbamoyl)- and C,C-bis(methoxycarbonyl)nitrones and subsequent rearrangements»

Tetrahedron Lett. 2014, 55, 3663-3666

DOI: 10.1016/j.tetlet.2014.04.107

The first example of 1,3-dipolar cycloaddition reactions of nitrones with arylallenes is described. C-Carbamoylnitrones react with the C1single bondC2 double bond of arylallenes affording the corresponding 4-methyleneisoxazolidines in good yields. N-Aryl-C,C-bis(methoxycarbonyl)nitrones usually gave rearranged products: mixtures of 4,5-dihydro-4-oxo-1H-benzo[b]azepine-2,2(3H)dicarboxylates and 4-oxo-1,5-diarylpyrrolidine-2,2-dicarboxylates.

17 июня в 15:00 в лектории Менделеевского центра состоится лекция профессора Hans-Heinrich Limbach из Dahlem Research School of Molecular Sciences of the Freie Universität Berlin, Germany:

«Functional hydrogen bond NMR: from model systems to nano catalysts and enzymes»

Адрес: СПб, Университетская наб. 7/9, здание НИХИ. Для прохода на территорию университета необходимо предъявить паспорт. Проезд на троллейбусах 1, 7, 10 и автобусах 7, 24, 47, 171. Справки по тел. 323-41-20.

P. R. Golubev, A. S. Pankova, M. A. Kuznetsov

“Transition-Metal-Free Approach to 4-Ethynylpyrimidines via Alkenynones”

Eur. J. Org. Chem. 2014, 3614-3621

DOI: 10.1002/ejoc.201402045

A practical approach to the synthesis of 4-ethynylpyrimidines by the condensation of arylamidines with 2-aryl-1-ethoxy-5-(trimethylsilyl)pent-1-en-4-yn-3-ones has been developed. As these latter ketones are easily accessible from bis(trimethylsilyl)acetylene and arylacetyl chlorides, the regioselective condensation reported herein provides a facile access to both TMS-protected and unprotected 4-ethynylpyrimidines in yields of up to 85%.