Categories: Synthesis of N-Heterocycles > Lactams
Synthesis of 5,6-dihydro-2-pyridinones
Recent Literature
Regioselective ring closing ene-yne metathesis provided an efficient access to
different substituted 1-benzazepine scaffolds. Five- and six-membered lactams
were efficiently prepared by ring-closing metathesis affording highly
functionalizable compounds.
E. Benedetti, M. Lomazzi, F. Tibiletti, J.-P. Goddard, L. Fensterbank, M.
Malacria, G. Palmisano, A. Penoni, Synthesis, 2012, 44,
3523-3533.
A Pd-catalyzed α,β-desaturation of N-protected lactams provides
conjugated unsaturated counterparts under mildly acidic conditions at room
temperature. The reaction tolerates a wide range of functional groups and shows
reactivity complementary to that of prior desaturation methods. Lactams with
various ring sizes and substituents at different positions all reacted smoothly.
M. Chen. G. Dong, J. Am. Chem. Soc., 2017,
139, 7757-7760.
An oxidative relay Heck arylation reaction enables the construction of chiral
α,β-unsaturated δ-lactams, widely used as pharmacophores, in high yields and
excellent enantioselectivities. This strategy also allows facile access to
7-substituted α,β-unsaturated ε-lactam products and δ-lactams.
Q. Yuan, M. S. Sigman, J. Am. Chem. Soc.,
2018,
140, 6527-6530.
A Pd-catalyzed arylation of aza-Achmatowicz rearrangement products
with arylboronic acids provides 2-aryldihydropyridinones
for facile synthesis of highly functionalized 2-arylpiperidines. Key to this
arylation is the use of non-phosphine-ligand palladium precatalyst. The utility of
2-aryldihydropyridinones is illustrated by the synthesis of a small collection
of 2-arylpiperidines.
G. Zhao, D. P. Canterbury, A. P. Taylor, X. Cheng, P. Mikochik, S. W. Bagley,
R. Tong,
Org. Lett., 2020, 22, 458-463.
In palladium-catalyzed regioselective [5 + 1] annulation reactions of vinyl
aziridines/epoxides with ClCF2COONa, vinyl aziridines/epoxides act as
heteroatom-containing five-atom synthons, and commercially available and cheap
ClCF2COONa is the carbonyl source. This protocol efficiently provides
δ-lactams and δ-lactones in good yields.
D. Zuo, T. Zhang, J. Zhao, W. Luo, C. Wang, P. Li, Org. Lett.,
2022, 24, 4630-4634.
A palladium-catalyzed carbonylative [5+1] cycloaddition of N-tosyl
vinylaziridines with CO provides α,β-unsaturated δ-lactams in dimethylformamide
and β,γ-unsaturated δ-lactams in tetrahydrofuran in very good yields.
T. Zhang, S. Wang, D. Zuo, J. Zhao, W. Luo, C. Wang, P. Li, J. Org. Chem., 2022, 87,
10372-10376.