Research output: Contribution to journal › Article
Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirinering expansion : Dedicated to Professor Armin de Meijere on the occasion of his 75th birthday. / Zavyalov, Kirill V.; Novikov, Mikail S.; Khlebnikov, Alexander F.; Pakalnis, Viktoriia V.
In: Tetrahedron, Vol. 70, No. 21, 2014, p. 3377-3384.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirinering expansion
T2 - Dedicated to Professor Armin de Meijere on the occasion of his 75th birthday
AU - Zavyalov, Kirill V.
AU - Novikov, Mikail S.
AU - Khlebnikov, Alexander F.
AU - Pakalnis, Viktoriia V.
PY - 2014
Y1 - 2014
N2 - The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative. © 2014 Elsevier Ltd. All rights reserved.
AB - The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative. © 2014 Elsevier Ltd. All rights reserved.
U2 - 10.1016/j.tet.2014.03.101
DO - 10.1016/j.tet.2014.03.101
M3 - Article
VL - 70
SP - 3377
EP - 3384
JO - Tetrahedron
JF - Tetrahedron
SN - 0040-4020
IS - 21
ER -
ID: 7004069