Center for Magnetic Resonance

J.J. Medvedev, O.S. Galkina, A.A. Klinkova, D.S. Giera, L. Hennig, C. Schneider, V.A. Nikolaev

“Domino [4 + 1]-annulation of α,β-unsaturated δ-amino esters with Rh(II)–carbenoids – a new approach towards multi-functionalized N-aryl pyrrolidines”

Org. Biomol. Chem., 2015, 13, 2640-2651

DOI: 10.1039/C4OB02454K

Catalytic decomposition of diazomalonates and other diazoesters using Rh(II)- and Cu(II)-complexes in the presence of α,β-unsaturated δ-(N-aryl)amino esters gives rise to the formation of multi-functionalized pyrrolidines with yields of up to 82%. The reaction apparently occurs as a domino process involving the initial N-ylide formation followed by intramolecular Michael addition to the conjugated system of amino esters to afford the pyrrolidine heterocycle. The whole process can also be classified as a [4 + 1]-annulation of the δ-amino α,β-unsaturated ester with the carbenoid intermediate.

D. Boyarskaya, M. Avdontceva, T. Chulkova

“Synthesis and crystal structure of 2-isocyano-4-methylphenyl diphenylacetate: a rare case of an easily accessible odourless isocyanide”

Acta Cryst. C, 2015, C71, 155-158

DOI: 10.1107/S2053229615001588

Acidic hydrogen containing 2-isocyano-4-methylphenyl diphenylacetate, C22H17NO2, (I), was synthesized by the base-promoted reaction between 5-methylbenzoxazole and diphenylacetyl chloride. Achiral (I) crystallizes in the chiral P212121 space group. The C[triple-bond]N bond length is 1.164 (2) Å and the angle between the OCO and 2-isocyano-4-methylphenyl planes is 69.10 (16)°. Molecules are linked via C=O…Hphenyl and bifurcated N[triple-bond]C…Hphenyl/N[triple-bond]C…Hmethine hydrogen bonds, forming one-dimensional arrays.

A.S. Bogachenkov, A.V. Dogadina, V.P. Boyarskiy, A.V. Vasilyev

“Acid-promoted transformations of 1-(diphenylphosphoryl)allenes: synthesis of novel 1,4-dihydrophosphinoline 1-oxides”

Org. Biomol. Chem., 2015, 13, 1333-1338

DOI: 10.1039/c4ob02269f

1-(Diphenylphosphoryl)alka-1,2-dienes (phosphonoallenes) in Brønsted (super)acids (TfOH, FSO3H, and H2SO4) at −70 to 120 °C for 30 min to 4 h gave, at first, (3-hydroxyalk-1-en-1-yl)diphenylphosphine oxides, as kinetically favorable reaction products, that are further converted into 1-phenyl-1,4-dihydrophosphinoline 1-oxides as thermodynamically stable compounds. The latter compounds are formed from phosphonoallenes under the action of a strong Lewis acid AlCl3 at room temperature for 10–120 min. This is a novel, simple and efficient (short reaction time, high yields) method for synthesis of such 1,4-dihydrophosphinoline 1-oxides.