Synthesis of thiocyanato-containing phenanthrenes and dihydronaphthalenes via Lewis acid-activated tandem electrophilic thiocyanation/carbocyclization of alkynes.Org Biomol Chem. 2023 Mar 15; 21(11):2417-2422.OB
A tandem electrophilic thiocyanation and cyclization of arene-alkynes has been developed under mild conditions, affording thiocyanato-substituted phenanthrenes, dihydronaphthalenes, 2H-chromenes and dihydroquinolines in moderate to excellent yields. This reaction provides an efficient protocol for the construction of C-SCN and C-C bonds in one step. In this transformation, N-thiocyanato reagent serves as a convenient precursor to transfer SCN+ in the presence of trimethylchlorosilane, and the cyclization exhibited exclusive 6-endo-dig selectivity. Finally, a gram scale reaction and further derivatizations highlight the utility of this synthetic strategy.