Photocyclization of Fluorinated Acetophenones Unlocks an Efficient Way to Solar Energy Storage.

The ability to store and release energy efficiently is crucial for advancing sustainable energy technologies, and light-driven molecular isomerization presents a promising solution. However, a persistent challenge in this field is achieving both high stability of the energy-storing photoisomer and establishing efficient catalysis for back-isomerization, a critical process for releasing the stored energy as heat. In this work, we introduce a conceptually new molecular system designed for long-term energy storage, which is based on the reversible isomerization of -methylacetophenone ⇄ benzocyclobutenol.

Ring opening of photogenerated azetidinols as a strategy for the synthesis of aminodioxolanes.

α-Aminoacetophenones are identified as promising building blocks for the synthesis of highly substituted dioxolanes. The presented strategy is founded on the build and release of molecular strain and achieves a formal transposition of a methyl group. During light irradiation, 3-phenylazetidinols are forged as reaction intermediates, which readily undergo ring opening upon the addition of electron-deficient ketones or boronic acids.

Dynamic kinetic resolution of transient hemiketals: a strategy for the desymmetrisation of prochiral oxetanols.

Identification of an electron poor trifluoroacetophenone allows the formation of uniquely stable hemiketals from prochiral oxetanols. When exposed to a cobalt(ii) catalyst, efficient ring-opening to densely functionalized dioxolanes is observed. Mechanistic studies suggest an unprecedented redox process between the cobalt(ii) catalyst and the hemiketal that initiates the oxetane-opening.