Ligand-controlled, Pd/CuH-catalyzed reductive cross-coupling of terminal alkenes and N-heteroaryl bromides

Chemoselective Hydroheteroarylation of Alkenes via Photoredox-Neutral Proton- and BF3-Mediated Electron Transfer

Herein, we have developed a complementary entry to enable hydroheteroarylation of alkenes involving basically photoredox dearomatizative heterocyclic carbon radical formation through acid-coupled electron transfer followed by Giese addition. While protonic solvent and thiophenol additive enabled two molecular hydroheteroarylations of alkenes, the nonproton environment with BF3 altered the chemoselectivity over cascade hydroheteroarylation of alkenes by radical addition of heteroaromatics with two molecular alkenes. This chemoselectivity can be mechanistically attributed to the dynamically favored hydrogen atom transfer via the cyclic transition state.

A Concise Route to Keto-Bridged Polyphenols by Photo-Fries Rearrangement in Flow

Described is a new synthetic route to bis(2-hydroxy-3,5-di-t-butylphenyl)methanone and its derivatives. The combined esterification/photo-Fries rearrangement approach enables a modular preparation of keto-bridged polyphenols. This protecting group-free process is highly atom- and step-economic, and a scalable production was easily achieved in the continuous-flow mode.

Electroreductive Cross-Electrophile Coupling (eXEC) Reactions

Electrochemistry utilizes electrons as a potent, controllable, and traceless alternative to chemical oxidants or reductants, and typically offers a more sustainable option for achieving selective organic synthesis. Recently, the merger of electrochemistry with readily available electrophiles has been recognized as a viable and increasingly popular methodology for efficiently constructing challenging C-C and C-heteroatom bonds in a sustainable manner for complex organic molecules. In this mini-review, we have systematically summarized the most recent advances in electroreductive cross-electrophile coupling (eXEC) reactions during the last decade. Our focus has been on readily available electrophiles, including aryl and alkyl organic (pseudo)halides, as well as small molecules such as CO2 , SO2 , and D2 O.