Synthesis of isoindolinones
Various N-substituted isoindolinones can be synthesized in excellent yields through the reductive C-N coupling and intramolecular amidation of 2-carboxybenzaldehyde with amines in the presence of ultrathin Pt nanowires as catalysts under 1 bar of hydrogen. These unsupported catalysts can also be used for the synthesis of phthalazinones in high yield when hydrazine or phenyl hydrazine is used instead of amines.
L. Shi, L. Hu, J. Wang, X. Cao, H. Gu, Org. Lett., 2012, 14, 1876-1879.
A copper-catalyzed sp3 C-H functionalization of 2-alkyl-N-substituted benzamides provides an efficient approach to various functionalized isoindolinones without preparation of halogenated substitutes, use of expensive transition metals, or toxic Sn or CO gas.
K. Nozawa-Kumada, J. Kadokawa, T. Kameyama, Y. Kondo, Org. Lett., 2015, 17, 4479-4481.
A palladium-catalyzed C-H carbonylation of readily available free primary benzylamines, in which NH2 acts as a chelating group, provides benzolactams under an atmospheric pressure of CO. Application of this new method is exemplified in the concise syntheses of two bioactive molecules.
C. Zhang, Y. Ding, Y. Gao, S. Li, G. Li, Org. Lett., 2018, 20, 2595-2598.
2-Benzyl-N-tosylbenzamides and related substrates undergo copper-catalyzed intramolecular benzylic sulfamidation to provide N-arylsuflonyl-1-arylisoindolinones.
R. B. Bedford, J. G. Bowen, C. Méndez-Gálvez, J. Org. Chem., 2017, 82, 1719-1725.
A new type of C2-symmetric chiral diene ligand was applied successfully in the Rh-catalyzed asymmetric arylation of N-tosylarylimines with arylboronic acids to give a broad range of highly enantiomerically enriched diarylmethylamines as well as 3-aryl substituted phthalimidines.
Z.-Q. Wang, C.-G. Feng, M.-H. Xu, G.-Q. Lin, J. Am. Chem. Soc., 2007, 129, 5336-5337.
Addition of o-iodobenzoyl chlorides to imines affords N-acyliminium ions as adducts. Subsequent reaction of these adducts with phenyllithium at -78˚C followed by warming to ambient temperature induces an intramolecular Wurtz-Fittig coupling to afford 2,3-dihydroisoindolones in excellent yields.
J. B. Campbell, R. F. Dedinas, S. Trumbower-Walsh, Synlett, 2010, 3008-3010.
An acylation/arylation reaction of α-aminoboronate salts with 2-bromobenzoyl chlorides provides isoindolinones in very good yields under mild conditions via an intramolecular, Cu-catalyzed sp3-sp2 coupling.
A. M. Dumas, A. J. Sieradzki, L. J. Donnelly, Org. Lett., 2016, 18, 1848-1851.
Copper(II) trifluoromethanesulfonate efficiently catalyzes the C-C coupling of 3-hydoxyisoindolinones with various aryl-, heteroaryl-, and alkenylboronic acids to furnish C(3)-substituted isoindolinones in 1,2-dicholoroethane (DCE) at reflux. The photolabile 2-nitrobenzyl protecting group is most appropriate for promotion of the coupling reaction and for deprotection.
H. S. P. Rao, A. V. B. Rao, J. Org. Chem., 2015, 80, 1506-1516.
An efficient palladium-catalyzed intramolecular cyclization of 2-iodobenzamides with a 2-oxoethyl function group on the nitrogen atom moiety provides 3-acyl isoindolin-1-ones and 3-hydroxy-3-acylisoindolin-1-ones under mild conditions in good yields.
W. Chen, L. Jin, Y. Zhu, X. Cao, L. Zheng, W. Mo, Synlett, 2013, 24, 1856-1860.
A cascade reaction enables a regiospecific synthesis of substituted 3-hydroxyisoindolinones under transition-metal-free conditions via base-mediated C-C bond coupling and N-α-sp3C-H bond hydroxylation. The procedure offers high regioselectivity, efficiency, and environmental friendliness. Various substituted 3-hydroxyisoindolinones, including some bioactive molecules, were provided in very good yields.
J. Shen, Q. You, Q. Fu, C. Kuai, H. Huang, L. Zhao, Z. Zhuang, Org. Lett., 2017, 19, 5170-5173.
Pd-Catalyzed Aminocarbonylation of the Blaise Reaction Intermediate: One-Pot Synthesis of (Z)-3-Methyleneisoindolin-1-ones from Nitriles
Z. Xuan, D. J. Jung, H. J. Jeon, S.-g. Lee, J. Org. Chem., 2016, 81, 10094-10098.