Organoboron-Promoted Electrochemical Chlorosulfonylation of Alkenes with Sulfonyl Chlorides.

Although extraordinary advances have been achieved by the transition-metal catalysis system, there is an urgent need to explore and develop alternative methodologies that are more environmentally friendly. Herein, we report an electrochemical chlorosulfonylation of alkenes using a wide range of sulfonyl chlorides with an inexpensive, degradable, and commercially available organoboron as a promoter. Furthermore, this protocol employs convergent paired electrolysis, reducing the need for sacrificial anodes and minimizing the extent of hydrogen evolution.

Electrochemical Cross-Dehydrogenative Aromatization Protocol for the Synthesis of Aromatic Amines.

The introduction of amines onto aromatics without metal catalysts and chemical oxidants is synthetically challenging. Herein, we report the first example of an electrochemical cross-dehydrogenative aromatization (ECDA) reaction of saturated cyclohexanones and amines to construct anilines without additional metal catalysts and chemical oxidants. This reaction exhibits a broad scope of cyclohexanones including heterocyclic ketones, affording a variety of aromatic amines with various functionalities, and shows great potential in the synthesis of biologically active compounds.

Practical Synthesis of ()-α,β-Unsaturated Nitriles via a One-Pot Sequential Hydroformylation/Knoevenagel Reaction.

Herein, the synthesis of ()-α,β-unsaturated nitriles by a sequential hydroformylation/Knoevenagel reaction has been first developed. A variety of crude α-olefins from Fischer-Tropsch synthesis, internal and special olefins, as well as alkynes could be transformed into value-added alkenyl nitriles (39 examples) up to 90% yield. Remarkably, compared with commonly used tedious multistep reactions, the one-pot protocol features cheap and easily available raw materials, excellent chemo-, regio-, and stereoselectivity, very mild reaction conditions, and easy scale-up production.

Selective Rhodium-Catalyzed Hydroformylation of Terminal Arylalkynes and Conjugated Enynes to (Poly)enals Enabled by a π-Acceptor Biphosphoramidite Ligand.

The hydroformylation of terminal arylalkynes and enynes offers a straightforward synthetic route to the valuable (poly)enals. However, the hydroformylation of terminal alkynes has remained a long-standing challenge. Herein, an efficient and selective Rh-catalyzed hydroformylation of terminal arylalkynes and conjugated enynes has been achieved by using a new stable biphosphoramidite ligand with strong π-acceptor capacity, which affords various important -(poly)enals in good yields with excellent chemo- and regioselectivity at low temperatures and low syngas pressures.