Categories: Synthesis of N-Heterocycles > benzo-fused N-Heterocycles >
Synthesis of phthalimides
Protecting Groups
Phthalimides
Recent Literature
A simple and practical benzannulation of maleimides with triethylamine as a
1,3-diene synthon provides phthalimides in good yields under mild conditions.
The transformation can be performed in the absence of a metal catalyst with high
levels of functional group tolerance.
L. Long, W. Wang, Y. Zhu, W. Luo, Y. Zhang, J. Chen, Y. Wei, Z. Chen, Org. Lett., 2023, 25,
7775-7779.
An efficient and simple method enables the N-alkylation of aromatic cyclic
imides using cesium carbonate as the base in anhydrous N,N-dimethylformamide
at low temperatures (20-70˚C). The employment of microwave irradiation presents
noteworthy advantages over conventional heating. The method is compatible with
base labile functional groups.
M. I. Escudero, L. D. Kremenchuzky, I. A. Perillo, H. Cerecetto, M. M. Blanco, Synthesis, 2011,
571-576.
Transition-metal-free multicomponent reactions involving arynes, isocyanides,
and CO2 as the third component resulted in the formation of N-substituted
phthalimides in good yields, whereas the use of water as the third component
furnished benzamide derivatives in good yields. These reactions took place under
mild conditions with broad scope.
T. Kaicharla, M. Thangaraj, A. T. Biju, Org. Lett., 2014,
16, 1728-1731.
In a palladium-catalyzed oxidative carbonylation reaction for the synthesis of
phthalimides, an imine and H2O, which are generated in situ from the
condensation of aldehyde and amine, serve as self-sufficient directing group and
nucleophile, respectively. This method provides rapid access to phthalimides
starting from readily available materials with high atom- and step-economy in a
one-pot manner.
F. Ji, J. Li, X. Li, W. Guo, W. Wu, H. Jiang, J. Org. Chem.,
2018, 83, 104-112.
L-proline catalyzes a reaction between α,β-unsaturated aldehydes and
maleimides to provide biologically and pharmaceutically important phthalimides.
The reaction involves an efficient benzannulation that proceeds via a formal [4
+ 2] cycloaddition of azadiene intermediates generated in situ from enals and
N-substituted maleimides.
M. S. Akhthar, Y. R. Lee, J. Org. Chem., 2020, 85,
15129-15138.
A metal-free photoredox catalyzed amidyl N-centered radical addition to the
C-C triple bond of o-alkynylated benzamides provides isoquinoline-1,3,4(2H)-triones,
3-hydroxyisoindolin-1-ones, and phthalimides via a proton-coupled electron
transfer (PCET) process under mild reaction conditions.
M. B. Reddy, K. Prasanth, R. Anandhan, Org. Lett.,
2022, 24, 3674-3679.
An efficient synthesis of 2-substituted 3-thioxoisoindolin-1-one derivatives is
based on the solvent-free reaction of 2-carboxybenzaldehyde with aliphatic
amines and sulfur at 100°C. This reaction enables a facile synthesis of
asymmetric thioxoisoindolin-1-one derivatives with phthalimide backbones.
F. Gholami, A. Moazzam, S. Bahadorikhalili, M. Adib, S. Hosseini, B. Larijani,
M. Mahdavi, Synlett, 2022,
33,
1729-1732.