Hydroxyl Assisted, Photoredox/Cobalt Co‐catalyzed Semi‐Hydrogenation and Tandem Cyclization of o ‐Alkynylphenols for Access to 2,3‐Dihydrobenzofurans

Renaissance in Alkyne Semihydrogenation: Mechanism, Selectivity, Functional Group Tolerance, and Applications in Organic Synthesis

Alkenes constitute a significant class of chemical compounds with applications in the bulk, pharmaceutical, or perfume industry. Among the known methods of olefin production, semihydrogenation of the C-C triple bond seems to be the most straightforward one. Nonetheless, the success of this reaction requires full control over diastereoselectivity, eradication of a parasitic process of over-reduction or migration of the C-C double bond formed, and achieving satisfactory functional-group compatibility. The review demonstrates developments in the field of alkyne semihydrogenation over the period 2010-2022, with selected papers published in 2023 and 2024, emphasizing solutions to the above-mentioned limitations. We discuss mechanistic aspects of this transformation, including those related to unconventional systems. The review includes examples of applications of alkyne semihydrogenation in organic synthesis, confirming the considerable utility of this process. Finally, strategies to enhance catalyst selectivity are summarized. For the reader's convenience, we provided a graphical guidebook to catalytic systems, illustrating the efficiency of the particular method.

Development of novel transition metal-catalyzed synthetic approaches for the synthesis of a dihydrobenzofuran nucleus: a review

The synthesis of dihydrobenzofuran scaffolds bears pivotal significance in the field of medicinal chemistry and organic synthesis. These heterocyclic scaffolds hold immense prospects owing to their significant pharmaceutical applications as they are extensively employed as essential precursors for constructing complex organic frameworks. Their versatility and importance make them an interesting subject of study for researchers in the scientific community. While exploring their synthesis, researchers have unveiled various novel and efficient pathways for assembling the dihydrobenzofuran core. In the wake of extensive data being continuously reported each year, we have outlined the recent updates (post 2020) on novel methodological accomplishments employing the efficient catalytic role of several transition metals to forge dihydrobenzofuran functionalities.

Visible-light enabled photochemical reduction of 1,2-dicarbonyl compounds by Hünig's base

A visible-light enabled, chemoselective photoreduction of 1,2-dicarbonyl compounds by using Hünig's base as reductant is reported.

The wavelength-regulated stereodivergent synthesis of (Z)- and (E)-1,4-enediones from phosphonium ylides

The wavelength-regulated, photoredox-catalyzed stereodivergent synthesis of (Z)- and (E)-1,4-enediones from phosphonium ylides is reported.