Transition-Metal-Free Iodine Catalyzed Selenocayanation of Styrenyl Bromides and an Easy Access to Benzoselenophenes via Intermediacy of Styrenyl Selenocyanate
Sulfur derivatives of 6,8-dioxabicyclo[3.2.1]octanes related to a number of natural products have been synthesized by the click hydrothiolation (AIBN or UV irradiation) of 7-methylene-6,8-dioxabicyclo[3.2.1]octanes, assembled from acetylene and ketones in a one-pot transition-metal-free synthetic operation. An unusual feature of this free-radical reaction is that it is accelerated in the presence of bases due to involvement of the latter in a competition between the thiol addition and proton-catalyzed isomerization of the starting bicyclooctanes.
A Brønsted acid-mediated addition of (hetero)aryl and (cyclo)alkyl sodium sulfinates to <i>N</i>-allenyl derivatives is described under very smooth conditions. This reaction provided a practical and efficient protocol for the synthesis of allylic sulfones in an atom- and step-economic fashion. In addition, an one-step double hydrosulfonylation has also been demonstrated, affording the corresponding 1,3-disulfone in to good yield.<br>
A Brønsted acid-mediated addition of (hetero)aryl and (cyclo)alkyl sodium sulfinates to <i>N</i>-allenyl derivatives is described under very smooth conditions. This reaction provided a practical and efficient protocol for the synthesis of allylic sulfones in an atom- and step-economic fashion. In addition, an one-step double hydrosulfonylation has also been demonstrated, affording the corresponding 1,3-disulfone in to good yield.<br>
A transition-metal-free radical carbonylation of activated alkylamines with thiophenols has been successfully developed. Various thioesters were selectively produced with moderate to good yields.
Here we report a
visible-light-promoted metal-free regioselective C3-H trifluoromehtylation
reaction that proceeds via radical mechanism and which supported by control
experiments. The combination of photoredox catalysis and hypervalent iodine
reagent provides a practical approach for the present trifluoromethylation
reaction and synthesis of a library of trifluoromethylated indazoles.
Easy Access to Allylic Sulfones Through Transition-Metal-Free Hydrosulfonylation Of Allenes
