Azulenesulfonium and azulenebis(sulfonium) salts:Formation by interrupted Pummerer reaction and subsequent derivatisation by nucleophiles
In: López-Alled , C M , Martin , F J O , Chen , K Y , Kociok-Köhn , G , James , T D , Wenk , J & Lewis , S E 2020 , ' Azulenesulfonium and azulenebis(sulfonium) salts : Formation by interrupted Pummerer reaction and subsequent derivatisation by nucleophiles ' , Tetrahedron , vol. 76 , no. 49 , 131700 . https://doi.org/10.1016/j.tet.2020.131700
Azulenes undergo either single or dual S E Ar reactions depending on the nature of the sulfur(IV) electrophile employed. These electrophiles are generated in situ from either sulfoxides or sulfides. The resultant cationic or dicationic azulene products can undergo further derivatisation by means of nucleophilic attack at the sulfonium α-carbon. In the case of cycloalkyl azulenylsulfonium salts, this leads to ring-opened azulenylsulfide products. This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 665992
