Trifluoromethylation of Allenes: An Expedient Access to α‐Trifluoromethylated Enones at Room Temperature

Abstract

A silver(I) catalyzed regioselective trifluoromethylation of allenes using Langlois's salt (NaOSOCF3) is demonstrated. This transformation enables direct expedient access to α‐trifluoromethylated acroleins, which are valuable synthons for a number of pharmaceuticals and agrochemicals containing vinyl‐CF3 moieties. Versatility of this trifluoromethylation method has been established with good yield and excellent regioselectivity. Preliminary experiments and computational studies were carried out to elucidate the mechanistic insight of this protocol.

α‐Substituted Chalcones: A Key Review

“… [97] Moreover, two α‐CF 3 ‐chalcones were synthesized using a silver(I) catalyzed regioselective trifluoromethylation of allenes and Langlois's salt (NaOSOCF 3 ) (reaction 6, Figure 24). [98] …”

Mechanistic Aspects and Synthetic Applications of Radical Additions to Allenes

“…The synthesis of α-CF 3 acroleins 84 from the Ag(I)-catalyzed regioselective trifluoromethylation of allenes 83 in the presence of the Langlois reagent was described by Zanoni and Maiti in 2018 (Scheme 35). 57 Three key experiments helped to show the importance of air for a successful reaction, which requires the presence of a CF 3 radical intermediate. Recently, the transition-metal-catalyzed incorporation of CF 3 groups into allene substrates has attracted significant attention from multiple research groups.…”

Nickel Nanoparticle Catalyzed Mono‐ and Di‐Reductions of gem‐Dibromocyclopropanes Under Mild, Aqueous Micellar Conditions

“…[16,17] Along the way,w eh ave also explored the opportunity of running gas-evolving reduction reactions in aqueous micellar media, resulting in ab road portfolio of reductive reactions using nanoparticles (NPs). [18,19] Herein, we report the use of catalytic amounts of new nickel NPs that function as acatalyst for the reduction of gem-dibromocyclopropanes in aqueous solutions of TPGS-750-M, in the presence of NaBH 4 as the source of hydride ( Figure 3). Thet uning of conditions also allows access to mono-brominated cyclopropanes,b uilding blocks that allow for further derivatization.…”

“…The ability to run organic reactions in an aqueous medium, rather than in organic solvents, dramatically reduces the environmental impact associated with organic synthesis, as typified by comparisons of E Factors . Along the way, we have also explored the opportunity of running gas‐evolving reduction reactions in aqueous micellar media, resulting in a broad portfolio of reductive reactions using nanoparticles (NPs) . Herein, we report the use of catalytic amounts of new nickel NPs that function as a catalyst for the reduction of gem ‐dibromocyclopropanes in aqueous solutions of TPGS‐750‐M, in the presence of NaBH 4 as the source of hydride (Figure ).…”