Categories: Synthesis of N-Heterocycles > Lactams >
Synthesis of β-lactams
Name Reactions
Recent Literature
Preferential Rh(II) carbenoid intramolecular C-H versus O-H insertion derived
from α-diazo-acetamides can be achieved in water by creating a large hydrophobic environment around the reactive carbenoid center using an
appropriate combination of the catalyst and amide groups.
N. R. Candeias, P. M. P. Gois, C. A. M. Afonso, J. Org. Chem., 2006, 71, 5489-5497.
N-Tosyl-3-halo-3-butenylamines underwent efficient Ullmann-type
coupling to afford 2-alkylideneazetidines, which could be readily converted to
the corresponding β-lactams by oxidation with O3.
H. Lu, C. Li, Org. Lett., 2006, 8, 5365-5367.
A catalytic, highly diastereoselective synthesis of trans-β-lactams is
based on a phosphonium fluoride precatalyst that both activates the nucleophile
and directs the reaction process for high yield and diastereoselectivity.
C. J. Abraham, D. H. Paull, C. Dogo-Isonagie, T. Lectka, Synlett, 2009,
1651-1654.
A chiral N-heterocyclic carbene catalyzed the Staudinger reaction of
arylalkylketenes with a variety of N-tert-butoxycarbonyl arylimines to
give the corresponding cis-β-lactams in good yields with good
diastereoselectivities and excellent enantioselectivities.
A.-R. Zhang, L. He, X. Wu, P.-L. Shao, S. Ye, Org. Lett., 2008,
10, 277-280.
A catalytic enantioselective Staudinger reactions is described that
preferentially furnish trans β-lactams. The use of an N-triflyl
protecting group for the imine is crucial for the success of the reaction.
E. C. Lee, B. L. Hodous, E. Bergin, C. Shih, G. C. Fu, J. Am. Chem. Soc.,
2005, 127, 11586-11587.
The Staudinger synthesis, an overall [2 + 2] cycloaddition of a ketene with
an imine, provides a nicely convergent route to biologically and
synthetically interesting β-lactams. A planar-chiral derivative of
4-(pyrrolidino)pyridine serves as a very effective enantioselective catalyst
coupling a range of symmetrical and unsymmetrical ketenes with various
imines with very good stereoselection and yield.
B. L. Hodous, G. C. Fu, J. Am. Chem. Soc., 2002, 124,
1578-1579.
Pd-Catalyzed Carbonylation of Diazo Compounds at Atmospheric Pressure: A
Catalytic Approach to Ketenes
Z. Zhang, Y. Liu, L. Ling, Y. Li, Y. Dong, M. Gong, X. Zhao, Y. Zhang, J. Wang, J. Am. Chem. Soc., 2011,
133, 4330-4341.
The transformation of diazoketones to ketenes can be realized not only by
utilizing photochemical reaction conditions but also under the action of
microwave irradiation. In the presence of imines, the generated ketenes
react further to afford β-lactams. Various trans-substituted
β-lactams derived from amino acids have been prepared.
M. R. Linder, J. Podlech, Org. Lett., 2001, 3, 1849-1851.
A practical methodology for the catalytic, asymmetric synthesis of β-lactams
results from the development of a catalyzed reaction of ketenes (or their
derived zwitterionic enolates) and imines using benzoylquinine as chiral
catalyst and proton sponge as the stoichiometric base.
A. E. Taggi, A. M. Hafez, H. Wack, B. Young, D. Ferraris, T. Lectka, J.
Am. Chem. Soc., 2002, 124, 6626-6635.
A general and highly efficient synthesis of 4-alkylidene-2-azetidinones was
achieved by the Cu(I)-catalyzed intramolecular C-N coupling of amides with vinyl
bromides. This 4-exo ring closure was found to be fundamentally preferred
over other modes (5-exo, 6-exo, and 6-endo) of cyclization
under copper catalysis.
Q. Zhao, C. Li, Org. Lett.,
2008, 10, 4037-4040.
