Solvent-Free and Catalyst-Free Chemistry Enables Insertion of Alkenes Into σ Bonds

The insertion of a double bond into a σ bond is widely implemented in organic chemistry, and its application in difunctionalization of alkenes has aroused considerable research interest owing to its superiority in synthetic efficiency. Additional catalysts or promoters are typically required to dissect stable σ bonds and initiate the insertion sequence; however, they result in some disadvantages such as high cost, poor accessibility, incompatibility of substrates, and strict requirements for experimental operations. Using the spontaneous cleavage of σ bonds and promoting effect of alkenes themselves, a new strategy for the insertion of alkenes into C–X (X = Cl, Br, or I) and N–F bonds is accomplished herein under solvent-free and catalyst-free conditions. Two promoting modes of olefins were verified via density functional theory calculations.