Description of solution

This innovation reports the first general photocatalyst-free cyclopropanation for substances with double bonds between carbon conjugates with an aromatic/heteroaromatic groups that uses underexploited gem-diiodomethyl carbonyl compounds as cyclopropanating reagents (Figure X) and a simple compact fluorescence lamp as a visible-light source. This process give rise to valuable cyclopropylcarboxylates that could be easily diversified. Cyclopropanation of styrene-like substrates can be carried out under visible light irradiation with no need of a sensitizer and using shelf-stable reagents.

This technology has an excellent functional group tolerance and has a high chemoselectivity that has enabled access to cyclopropyl carboxylates. The excellent functional group tolerance and chemoselectivity observed towards the styrene double bond are in sharp contrast to current catalytic methods that cyclopropanate styrenes involving electrophilic metal-carbenes from diazoacetates. One of the more important advantages is that the cyclopropanation reagent consist on a shelf-stable solid which makes it useful as a reagent. The synthesis of the reagent is easily scalable. Due to the mild conditions and metal-free cyclopropanation process, the process can be considered a green process.

Advantages and unique selling points

• Robust technology: The technology has been proved on 52 different substrates, including heterocycles and biomolecules, with up to 93% yield for the cyclopropanation product.
• Excellent functional group tolerance: This technology has an excellent functional group tolerance and has a high chemoselectivity that has enabled access to cyclopropyl carboxylates.
• Late-stage functionalization: As an additional advantage, the method tolerates very well the presence of functional groups on the reaction substrate, which makes it suitable for late-stage functionalization.
• Shelf-stable solid: The cyclopropanation reagent consist on a shelf-stable solid which makes it useful as a reagent.