We report the tandem base-promoted elimination/ring-opening of 2-benzyl-1,3-dithianes with subsequent cross coupling of the pendent thiol with a range of aryl bromides. A simple Pd(OAc)2/Xantphos catalyst system affects this new reaction and is compatible with a wide range of functional groups, including heteroaromatic coupling partners. The transformation proceeds in good to excellent yields (69-99%) and exhibits strong stereoselectivity, forming the E-alkene as the major diastereomer. This new methodology provides access to nonsymmetric propylene styryl/aryl dithioethers, a previously undisclosed motif.

Formation. -The reaction gives S-styryl/S-aryl dithioethers in high yields with excellent E selectivity. 2-Benzyl-1,3-dithiolane as substrate fails (decomposition only). The following reactants also show no coupling: p-nitrophenyl bromide, p-chloroanisol, phenyl triflate, 5-bromoindole and mesityl bromide. -(ABIDI, N.; SCHMINK*, J. R.; J. Org. Chem. 80 (2015) 8, 4123-4131, http://dx.doi.org/10.1021/acs.joc.5b00547 ; Dep. Chem., Bryn Mawr Coll., Bryn Mawr, PA 19010, USA; Eng.) -M. Tismer 34-121