Interrupted CuAAC-Thiolation for the Construction of 1,2,3-Triazole-Fused Eight-Membered Heterocycles from O-/N-Propargyl derived Benzyl Thiosulfonates with Organic Azides
A copper(I)-catalyzed interrupted click-sulfenylation of O-/N-propargyl benzyl thiosulfonates with organic azides has been disclosed. The unified CuAAC-thiolation provides a wide range of triazole-fused eight-membered heterocycles in good to high (51–94%) yields under mild reaction conditions. Moreover, a three-component reaction is also achieved involving O-/N-propargyl benzyl thiosulfonates, benzyl bromide, and sodium azide to deliver fused-triazoles in 61–74% yields. From a synthetic point of view, the present protocol has been demonstrated at gram-scale reactions. A plausible mechanism is also proposed based on experimental results and control experiments. (Figure presented.).
Benzopentathiepin as Sulfurization Reagent. Novel Synthesis of Thiosulfonates from Sulfinates
Sodium alkane- and arenesulfinates were readily sulfurized with benzopentathiepin in usual organic solvents at room temperature to give corresponding thiosulfonates in good yields.