The reactions of
β-aminoethanethiol with <i>N</i>,<i>N</i>-dimethyl enaminones are performed to selectively
provide disulfide-functionalized enaminones and 1,4-thiazines. By
performing the reaction in water and catalyst-free conditions, the
transamination and oxidative S–S coupling between the two substrates
take place to give disulfide-functionalized enaminones. On the other
hand, by using identical starting materials, the employment of the
CuI catalyst in dimethyl sulfoxide enables the selective generation
of 1,4-thiazines via tandem transamination and C(sp<sup>2</sup>)–H
bond thiolation
