Categories: Synthesis of O-Heterocycles > benzo-fused O-Heterocycles >
Synthesis of isochromans
Recent Literature
A nucleophilic substitution of alkyl fluorides was achieved in intramolecular
reactions with O- and N-nucleophiles. The reaction is influenced by the nature
of nucleophiles, the size of the ring to be formed, and the comformational
rigidity of the precursors.
L. Zhang, W. Zhang, J. Liu, J. Hu, J. Org. Chem., 2009,
74, 2850-2853.
The use of [bis(trifluoroacetoxy)iodo]benzene as stoichiometric oxidant and
2,3-dichloro-5,6-dicyano-1,4-benzoquinone as organocatalyst enables a convenient
oxidation of isochromans. A further reaction with grignard reagents or amides
affords the corresponding isochroman derivatives.
W. Muramatsu, K. Nakano, Org. Lett., 2014,
16, 2042-2045.
A transition-metal-free coupling of various triorganoindium reagents with
chromene and isochroman acetals in the presence of BF3ˇOEt2
afforded 2-substituted chromenes and 1-substituted isochromans, respectively, in
good yields. The reactions proceed with only 50 mol % of the organometallic,
thus demonstrating the efficiency of these species.
J. M. Gil-Negrete, J. P. Sestelo, L. A. Sarandeses, Org. Lett.,
2016, 18, 4316-4319.
An efficient and convenient electrochemical cross-dehydrogenative coupling
reaction between isochroman and unactivated ketones provides α-substituted
isochromans without external oxidants. The method offers high atom economy and
mild conditions with methanesulfonic acid (MsOH) as both electrolyte and
catalyst.
H. Cao, C.-J. Long, D. Yang, Z. Guan, Y.-H. He, J. Org. Chem., 2023, 88,
4145-4154.