Most of the efforts of organic chemists have been directed to the development of creative strategies to build carbon-carbon and carbon-heteroatom bonds in a predictable and efficient manner. In this Review, we show an alternative approach where challenging molecular skeletons could be prepared through selective cleavage of carbon-carbon bonds. We demonstrate that it has the potential to be a general principle in organic synthesis for the regio-, diastereo-, and even enantioselective preparation of adducts despite the fact that C-C single bonds are among the least reactive functional groups. The development of such strategies may have an impact on synthesis design and can ultimately lead to new selective and efficient processes for the utilization of simple hydrocarbons.

The copper-catalyzed carbomagnesiation reaction of cyclopropenyl esters 1 leads to various substituted cyclopropanes species 3 in good yields with very high diastereoselectivities. The reaction proceeds through a syn-chelated carbomagnesiation reaction and could be extended to various cyclopropenylmethyl ester derivatives 5. The potential of this approach was illustrated by the preparation of two consecutive all-carbon quaternary stereocenters. However, the carbometalation reaction needs to be performed at temperature ranging from -35 to -20 °C to avoid subsequent fragmentation reaction into stereodefined β,γ-nonconjugated unsaturated esters 4. Alternatively, the carbocupration reaction with organocopper species could also be performed to leads to configurationally stable cyclopropyl copper species 2[Cu]. Additionally, when the Lewis acid character of the copper center is decreased (i.e., RCuCNLi), the reaction proceed with an anti-selectivity. The diastereodivergent behavior of these organometallic species is of synthetic interest, since both diastereomers syn-3 and anti-3 can be obtained, at will, from the same precursor cyclopropenyl esters 1.

A twofer: The title reaction sequence for cyclopropenes allows the preparation of aldehydes bearing α‐quaternary stereocenters in a one pot‐reaction from readily available starting materials. Through a diastereodivergent carbometalation reaction, both enantiomers of the corresponding aldehyde were obtained from the same cyclopropene derivative (see scheme).

The diastereoselective carbocupration reaction of cyclopropenylmethyl ethers followed by addition of oxenoid leads to the formation of diastereo- and enantiomerically enriched 2,2,3,3-tetrasubstituted cyclopropanol derivatives. Ring fragmentation of the copper cyclopropanolate leads to acyclic butenal derivatives possessing enantiomerically enriched α-quaternary carbon stereocenters in a single-pot operation.

Herein, we present the first Suzuki–Miyaura cross-coupling in a sustainable natural deep eutectic solvent (NaDES) applied to biologically relevant imidazo-fused scaffolds imidazo[1,2-a]pyridine and imidazo[1,2-b]pyridazine. The choline chloride/glycerol (1:2, mol/mol) NaDES allowed the functionalisation of diverse positions on the heterocycles with various boronic acids, by using 2.5 mol% of readily available Pd(OAc)2. Notably, the catalytic system proceeds without any ligands or additives, without protection from the atmosphere.