For the initial phase of the project, S-methyl-S-phenylsulfoximine (1a) and 1-bromo-2-phenylacetylene (5a) were chosen as substrates, which we expected to provide N-alkynylated sulfoximine 3a after the coupling. Because of the particular properties of the sulfoximines, an extensive screening of reaction conditions was necessary to get the first positive results. Ultimately, a slightly modified procedure of Hsung's original protocol(13d) as described by Yorimitsu, Oshima, and co- ...
