Deconstructive Carboxylation of Activated Alkenes with Carbon Dioxide.

Carboxylation with carbon dioxide (CO2 ) represents one notable methodology to produce carboxylic acids. In contrast to carbon-heteroatom bonds, carbon-carbon bond cleavage for carboxylation with CO2 is far more challenging due to their inherent and less favorable orbital directionality for interacting with transition metals. Here we report a photocatalytic protocol for the deconstructive carboxylation of alkenes with CO2 to generate carboxylic acids in the absence of transition metals. It is emphasized that our protocol provides carboxylic acids with obviously unchanged carbon numbers when terminal alkenes were used. To show the power of this strategy, a variety of pharmaceutically relevant applications including the modular synthesis of propionate nonsteroidal anti-inflammatory drugs and the late-stage carboxylation of bioactive molecule derivatives are demonstrated.

Building a cobaloxime-based metal-organic framework for photocatalytic aerobic oxidation of arylboronic acids to phenols.

Herein, the design and synthesis of an unprecedented cobaloxime-based zirconium metal-organic framework (Zr-TCPCo) with an she net is reported. This heterogeneous material as a photocatalyst exhibits excellent catalytic activity for aerobic oxidation of arylboronic acids to phenols. Recycling experiments demonstrate the stability and reusability of Zr-TCPCo as a robust catalyst.

Photoinduced synthesis of fluorinated dibenz[b,e]azepines via radical triggered cyclization.

A simple, mild and efficient approach to access fluorinated dibenz[b,e]azepines via visible-light photoredox catalysis is presented. Inexpensive and commercially available fluoroalkyl anhydrides in concert with pyridine N-oxide are employed as the source of the fluoroalkyl radicals. A one-pot process involving the trifluoroacetylation of unprotected secondary benzyl amines followed by radical cyclization could also afford the desired fluorinated dibenz[b,e]azepines.