Fluorine-Assisted Rearrangement of Geminal Azidofluorides to Imidoyl Fluorides

Abstract

Organoazide rearrangement constitutes versatile synthetic strategies but typically requires an extremely strong acid and/or a high reaction temperature. Our group recently discovered the remarkable accelerating effect of the geminal fluorine substituent that enables the facile rearrangement of azides into imidoyl fluorides without the aid of acid under much milder reaction conditions. The role of geminal fluorine was elucidated by both experimental and computational investigations. This new reactivity led to the development of a practical one-step tandem preparative method for potentially useful and bench-stable imidoyl fluorides from a wide range of structurally diverse geminal chlorofluorides. Our additional efforts to expand the reaction scope regarding the migrating group, halogen, and carbonyl function are described, and the synthetic utility of the imidoyl fluoride products was demonstrated in hopes of promoting the use of this under-appreciated functional group in the synthetic organic community.

Photoinduced copper-catalyzed C–N coupling with trifluoromethylated arenes

“…To our surprise, the resulting α,α-difluoromethylamines was immediately transformed to imidoyl fluorides through tandem C–N coupling and defluorination under basic conditions (Supplementary Table 10 ) 66 . Despite of the promising synthetic potential of imidoyl fluorides, their synthesis is challenging and in general harsh reaction conditions are required while with limited scope 67 – 70 . A series of structurally diverse imidoyl fluorides ( 9a – 9n ) can be readily obtained in synthetically useful yields from commercially available trifluoromethylated arenes and aromatic amines as shown in Fig.…”

Relayed Heteroatom Group Transfer: A Structural Reorganization between Bisthioester and Triaminophosphine to α,α-Disulfenylamide

“…The heterocycles derived from 1,2-dicarbonyl compounds and P­(III) reagents via [4 + 1] cycloaddition can react sequentially with an electrophile and a nucleophile, thus exhibiting carbene-like characteristics. Our group has been interested in this reactivity of dioxaphospholenes and developed various geminal fluorofunctionalizations of 1,2-diketones . While examining other types of 1,2-dicarbonyl compounds that were expected to have similar electronic properties to 1,2-diketones such as bisthioester 1 , we discovered an unexpected structural reorganization to α,α-disulfenylamide 2 upon treatment with phosphoramidite (Figure C).…”