Coupling of thiols and aromatic halides promoted by diboron derived super electron donors

Single-Electron Reduction of "Push-Pull" C-C Single Bond and Decyanation Using Tertiary Amines as the Organic Electron Donor

Using commercially available tertiary amines as an organic electron donor (OED), the reduction of "push-pull" C-C single bond and reductive decyanation of tetrahydroisoquinolines were realized. These reactions exhibited higher reaction efficiency and better functional group tolerance compared with those of metallic reductants, and the mechanistic study indicated that a radical intermediate was involved in the reduction of the C-C single bond, which provides a new way to the OED-enabled mild reduction.

Synthesis of Asymmetric Diaryl Sulfides via HI-Mediated C(sp2)-H Sulfenylation of Arenes with Sodium Sulfinates

A novel hydroiodic acid-promoted metal-free C(sp²)-H sulfenylation of electron-rich arenes was developed using stable and easy-to-handle sodium sulfinates as sulfur sources. Diverse kinds of asymmetric aryl sulfides were afforded in good yields from various commercially available aromatic substrates under mild conditions. Comprehensive mechanistic experiments demonstrate that RSO₂SR and RSSR are the key intermediates responsible for the redox process.

Diboron reagents in the deoxygenation of nitrones

B₂nep₂ efficiently promotes the N-O cleavage of nitrones to form imines in very high yields via a simple, efficient, sustainable, functional group tolerant and scalable protocol. The reaction occurs in the absence of additives through a concerted mechanism. We demonstrated that DMPO and TEMPO, typically used as radical traps, are also deoxygenated by diboron reagents, which demonstrates their limitation as mechanistic probes.

Sustainable Thioetherification via Electron Donor-Acceptor Photoactivation Using Thianthrenium Salts

The synthesis of sulfides has been widely studied because this functional subunit is prevalent in biomolecules and pharmaceuticals, as well as being a useful synthetic platform for further elaboration. Thus, various methods to build C-S bonds have been developed, but typically they require the use of precious metals or harsh conditions. Electron donor-acceptor (EDA) complex photoactivation strategies have emerged as versatile and sustainable ways to achieve C-S bond formation, avoiding challenges associated with previous methods. This work describes an open-to-air, photoinduced, site-selective C-H thioetherification from readily available reagents via EDA complex formation that tolerates a wide range of different functional groups. Moreover, C(sp2 )-halogen bonds remain intact using this protocol, allowing late-stage installation of the sulfide motif in various bioactive scaffolds, while allowing yet further modification through more traditional C-X bond cleavage protocols. Additionally, various mechanistic investigations support the envisioned EDA complex scenario.