Solvent-free mechanochemical chlorination of hydrocarbons with CuCl2

Oxidative Free-Radical C(sp2)–H Bond Chlorination of Enaminones with LiCl: Access to Highly Functionalized α-Chlorinated Enaminones

“…Based on the above experimental results and literature reports, ,, a plausible mechanism for this transformation is speculated in Scheme . The reaction is believed to proceed via in situ generation of Cl• from LiCl in the presence of the oxidants.…”

“…3 In recent years, some strategies for introducing C−Cl bonds by metal chlorides, due to their stable and easily preserved chlorinating reagents, have attracted significant interest within the chemical community. 4 Compared with CuCl 2 and FeCl 3 , LiCl and NaCl have more advantages in terms of price and access (Scheme 1c,d). Although it might be a more efficient option in certain cases, this chlorination strategy has been established far less well due to the difficulty in activating the low chemical activity of chloride ions.…”

“…Some nonsalt inorganic chlorinating reagents, such as Cl 2 , HCl, PCl 3 , SOCl 2 , etc., are the most traditional strategies for constructing C–Cl bonds, but they are limited by high toxicity, difficult storage, lack of control, low reaction efficiency, and so on (Scheme b) . In recent years, some strategies for introducing C–Cl bonds by metal chlorides, due to their stable and easily preserved chlorinating reagents, have attracted significant interest within the chemical community . Compared with CuCl 2 and FeCl 3 , LiCl and NaCl have more advantages in terms of price and access (Scheme c,d).…”

Metal-catalyzed organic reactions using mechanochemistry

“…Examples of such metalmediated reactions include the oxidative homocoupling of phenols catalyzed by FeCl 3 ·6H 2 O, 84 the Mn(OAc) 3 -mediated formation of benzofuranone and dihydrobenzofuran derivatives, 85 the mechanochemical self-aldol reaction of valeraldehyde facilitated by aluminum, 86 the chlorination of hydrocarbons by CuCl 2 in a ball mill 87 and reduction of nitro groups by elementary metals. 88 Due to the space limitations, and the existence of excellent reviews and studies addressing such reactions in more detail, 1,89 we have decided to highlight only the most recent contributions to this field.…”