Categories: Synthesis of S-Heterocycles > benzo-fused S-Heterocycles >
Synthesis of thiochromones and thioflavones
Recent Literature
A one-pot Friedel-Crafts acylation of alkynes with suitably substituted benzoyl
chlorides provides chromenones and thiochromenones. The ready availability of
both starting materials, alkynes and benzoyl chlorides, coupled with the
experimental simplicity makes the current synthetic method to (thio)chromenones
fast, efficient, and practical.
H. Y. Kim, E. Song, K. Oh, Org. Lett.,
2017, 19, 312-315.
4-Quinolones and 4H-thiochromen-4-ones are readily synthesized in a
tandem one-pot manner from (Z)-β-chlorovinyl ketones in in good to
excellent yields. An intermolecular nucleophilic addition of amines or sodium
hydrogen sulfide to (Z)-β-chlorovinyl ketones is followed by elimination of a
chlorine anion to give a Z-enamine or thioenol intermediate, which gives
the desired products through intramolecular SNAr reaction.
D. Wang, P. Sun, P. Jia, J. Peng, Y. Yue, C. Chen, Synthesis, 2017,
49, 4309-4320.
A rhodium-catalyzed carbonylative annulation methodology with nonactivated
aromatic sulfides and terminal alkynes as the substrates provides
thiochromenones effectively via [3 + 2+1]-type annulation.
F. Zhu, X.-F. Wu, J. Org. Chem., 2018, 83,
13612-13617.
A copper-catalyzed intramolecular ring opening of donor-acceptor cyclopropanes
in the presence of xanthate as a sulfur surrogate enables the synthesis of
3-alkyl-carbonated thioflavones and 3-alkyl-carbonated thioflavothiones.
N. Sundaravelu, G. Sekar,
Org. Lett., 2019, 21, 6648-6652.
A mild ICl-induced cyclization of heteroatom-substituted alkynones provides
a simple, highly efficient approach to various 3-iodochromones,
iodothiochromenones, iodoquinolinones and analogues in good to excellent
yields. Subsequent palladium-catalyzed transformations afford a rapid
increase in molecular complexity.
C. Zhou, A. V. Dubrovsky, R. C. Larock, J. Org. Chem., 2006, 71,
1626-1632.