37 / 2023-08-09 14:40:43

Diformyloxylation of Unactivated Alkenes with Formic Acid

Diformyloxylation; Unactivated alkenes; Formic acid

New Technologies in Phosphorus Chemistry > 1) New reagents and methods in organophosphorus Chemistry

Alkene dioxygenation serve as a straightforward and powerful transformation for the preparation of 1,2-diol skeletons which are widely exiting in pharmaceuticals and bioactive natural products. Versatile strategies have been developed to modulate such reaction, including Prévost-Woodward reaction, Sharpless reaction, metal-participated or metal-free dioxygenations. We disclosed a novel and efficient diformyloxylation of allylphosphorates with the employment of DIH as the mediator and formic acid as the formyloxylating reagent. Good functionality compatibility was achieved and homoallyl phosphoric compounds could also participated in the diformyloxylation with good yields. Whereas, other types of carboxylic acids gave the iodoesterification mixtures under same conditions, and other types of allylic alkenes showed inert reactivity. Reaction monitoring and radical inhibition experiments revealed that the diformyloxylation might proceed with a DIH-mediated ionic iodoformyloxylation process, followed by a DIH-mediated radical process which might involve a intramolecular H-bonding between C-I bond and acyl hydrogen of the iodoformyloxylation products (Figure 1).