TY - JOUR

T1 - Assembly of spiro β-lactams by Rh(ii)-catalyzed reaction of diazocarbonyl compounds with azirines/isoxazoles

AU - Golubev, Artem A.

AU - Smetanin, Ilia A.

AU - Agafonova, Anastasiya

AU - Rostovskii, Nikolai

AU - Khlebnikov, Alexander F.

AU - Starova, Galina L.

AU - Novikov, Mikhail S.

N1 - Funding Information: We gratefully acknowledge the financial support of the Russian Foundation for Basic Research (project no. 16-03-00596). This research used resources of the Magnetic Resonance Research Centre, Chemical Analysis and Materials Research Centre, Centre for X-ray Diffraction Studies, and Chemistry Educational Centre of the Research Park of St. Petersburg State University. Publisher Copyright: © The Royal Society of Chemistry 2019.

PY - 2019/7/28

Y1 - 2019/7/28

N2 - A domino synthesis of dispiro-fused N-vinyl beta-lactams from diazo-Meldrum's acid and 2H-azirines or 5-alkoxyisoxazoles via the "2-azabuta-1,3-diene formation/Staudinger ketene-imine cycloaddition" sequence is described. The Rh-2(Piv)(4)-catalyzed formation of the 2-azabuta-1,3-diene intermediates in the first stage of the reaction sequence proceeds via addition of the rhodium carbenoid to the azirines/isoxazoles and provides the first example of the generation of iminium-type ylides from diazo-Meldrum's acid. This methodology was extended to monospiro-beta-lactams, which were synthesized in two steps using acyclic alpha-diazocarbonyl compounds in the stage of the formation of 2-azabuta-1,3-dienes. The method allows for the rapid assemblage of the carbon part of the azetidin-2-one system from diazo compounds only and affords spiro- and dispiro-beta-lactams in moderate yields. A bromine atom in the 2-bromoalkenyl moiety of the synthesized beta-lactams can be easily substituted by hydrogen under catalytic hydrogenation conditions or by 2-pyridyl-substituent via the Stille cross-coupling reaction.

AB - A domino synthesis of dispiro-fused N-vinyl beta-lactams from diazo-Meldrum's acid and 2H-azirines or 5-alkoxyisoxazoles via the "2-azabuta-1,3-diene formation/Staudinger ketene-imine cycloaddition" sequence is described. The Rh-2(Piv)(4)-catalyzed formation of the 2-azabuta-1,3-diene intermediates in the first stage of the reaction sequence proceeds via addition of the rhodium carbenoid to the azirines/isoxazoles and provides the first example of the generation of iminium-type ylides from diazo-Meldrum's acid. This methodology was extended to monospiro-beta-lactams, which were synthesized in two steps using acyclic alpha-diazocarbonyl compounds in the stage of the formation of 2-azabuta-1,3-dienes. The method allows for the rapid assemblage of the carbon part of the azetidin-2-one system from diazo compounds only and affords spiro- and dispiro-beta-lactams in moderate yields. A bromine atom in the 2-bromoalkenyl moiety of the synthesized beta-lactams can be easily substituted by hydrogen under catalytic hydrogenation conditions or by 2-pyridyl-substituent via the Stille cross-coupling reaction.

KW - CARBENOID FUNCTIONALIZATION

KW - RHODIUM CARBENOIDS

KW - CYCLOADDITION REACTION

KW - DIAZO-COMPOUNDS

KW - KETENES

KW - IMINES

KW - ESTERS

KW - DIAZOKETONES

KW - INSERTION

KW - COPPER

UR - http://www.scopus.com/inward/record.url?scp=85069206875&partnerID=8YFLogxK

UR - http://www.mendeley.com/research/assembly-spiro-%CE%B2lactams-rhiicatalyzed-reaction-diazocarbonyl-compounds-azirinesisoxazoles

U2 - 10.1039/c9ob01301f

DO - 10.1039/c9ob01301f

M3 - статья

VL - 17

SP - 6821

EP - 6830

JO - Organic and Biomolecular Chemistry

JF - Organic and Biomolecular Chemistry

SN - 1477-0520

IS - 28

ER -