Solvent-Directed Transition Metal-Free C-C Bond Cleavage by Azido-1,3,5-triazines and Their Stability-Reactivity Paradox

Demethyl oxidative halogenation of diacyl dimethylsulfonium methylides

α-Halo-α-methylthio-β-ketosulfones containing a quaternary halocarbon stereocenter were prepared via selective demethyl oxidative halogenations of diacyl dimethylsulfonium methylides in moderate to excellent yields (39 examples; up to 98%). The current protocols directly and efficiently introduce a halogen atom into organic compounds with high functional group tolerance under metal-free conditions.

Metal-Free Catalysis in C-C Single-Bond Cleavage: Achievements and Prospects

This review article emphasizes the C-C bond cleavage in organic synthesis via metal-free approach. Conventional organic synthesis mainly deals with the reactive π bonds and polar σ bonds. In contrast, the ubiquitous C-C single bonds are inherently stable and are less reactive, which poses a challenge to synthetic chemists. Although inert, such C-C single-bond cleavage reactions have gained attention amongst synthetic chemists, as they provide unique and more straightforward routes, with significantly fewer steps. Several review articles have been reported regarding the activation and cleavage of C-C bonds using different transition metals. However, given the high cost and toxicity of many of these metals, the development of strategies under metal-free conditions is of utmost importance. Though many research articles have been published in this area, no review article has been reported so far. Herein, we discuss the reactions in a more concise way from the year 2012 to today, with emphasis on important reactions. Mechanisms of all the reactions are also well addressed. We believe that this review will be beneficial for the readers who work in this field.