Synthesis of thioflavones
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.
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.