The Photocatalytic Amination and Sulfuration of Heteroarenes

20 W fluorescent lamp 0.5 mol% fac-lr(dFppy)3 20 mol% AcOH, 3 equiv. K2CO3 CH3CN, rt 

Soon after, Xue s group also demonstrated a visible-light photocatalytic transformation of chloroamines to nitrogen-centered radicals. This strategy was utilized for the direct C-H amination of benzoxazoles in a one-pot, two-step process (Eq. (13.27)) [76]. This one-pot process circumvents the needs for purification of the chloroamines, showing the potential of this amination for synthetic applications. 

In 2014, Yu and coworkers used the hydroxylamine derivative Af,0-ditosyl-JV-methylhydroxylamine 273 as a tunable nitrogen source for the direct C-H amida-tion of heteroarenes through a visible-light-mediated photocatalytic method (Eq. (13.28)) [77a]. A variety of heteroarenes, such as indoles, furans, and pyrroles, smoothly underwent this amidation reaction at room temperature. Very recently, Studer successfully introduced Af-aminopyridinium salts, which are readily prepared from cheap starting materials, as efficient Af-centered radical precursors. These novel Af-radical precursors can be used for the direct C-H amidation of 

---