Cobalt‐Catalyzed Coupling of Alkyl Iodides with Alkenes: Deprotonation of Hydridocobalt Enables Turnover

Abstract

Unverzichtbare Base: Die Cobaltkomplexe I und II katalysieren intramolekulare Kupplungen vom Alkyl‐Heck‐Typ zwischen Alkyliodiden und Alkenen bei der Bestrahlung mit sichtbarem Licht, wenn ein tertiäres Amin als Base zugegen ist. Die Methode ist mit einer großen Bandbreite an funktionellen Gruppen kompatibel, was auf vielseitigen Einsatz in der Synthese hoffen lässt.

Silylium‐Catalyzed Carbon–Carbon Coupling of Alkynylsilanes with (2‐Bromo‐1‐methoxyethyl)arenes: Alternative Approaches

“…[4] Furthermore, the formation of (1-methoxyoctane-1,3-diyl)dibenzene (eq 2) was noticed in the alkylation of 2bromo-1-methoxyethyl)benzene with alkyl halides catalyzed by Cp2TiCl2, [5] suggesting that styrene is released and incorporated into the catalytic cycle. [5b] Photocatalytic radical cyclizations (eq 4) giving Heck-like products, [6] and nickel-catalyzed Suzuki cross-coupling with boronic acids (eq 5). [7] have been disclosed.…”

Visible-Light-Mediated NHC and Tertiary Amine Catalysis Enabling α-H Acylation of Alkenes

“…Linear molecules are obtained via photoredox or transition-metal-catalyzed Mizoroki-Heck reactions of alkenes, which have been abundantly reported . Relatively, there are a few methods to activate olefins’ α-C–H to cultivate a branched chain structure.…”

“…Linear molecules are obtained via photoredox or transitionmetal-catalyzed Mizoroki-Heck reactions of alkenes, which have been abundantly reported. 3 Relatively, there are a few methods to activate olefins' α-C−H to cultivate a branched chain structure. Recently, Leyva-Peŕez's 4 and Goẗtker-Schnetmann's 5 groups reported electron-poor alkene selective α-arylation.…”

“…Next, we investigated other photocatalysts, covering [Ir(dtbbpy)(ppy) 2 ]PF 6 , Ir[dF(CF 3 )ppy] 2 (dtbbpy)PF 6 , Ru-(bpy) 3 (PF 6 ) 2 , and fac-Ir(ppy) 3 under identical conditions (Table 1, entries 6−9). Among them, [Ir(dtbbpy)(ppy) 2 ]PF 6 displayed the highest reactivity, while fac-Ir(ppy) 3 and Ru(bpy) 3 Cl 2 photocatalytic systems hardly delivered any products. In order to improve the yield of the desired product, the different solvents, NHC catalysts, and number of equivalents of base were examined.…”

Photoinduced Cobalt Catalyzed Radical Heck-Type Reaction of Alkyl Electrophiles

“…Ether or thioether as well as protected amine was tolerated under the standard reaction conditions (10−13). Secondary alkyl iodides could afford the coupling products as well, albeit the yields are moderate, which is likely because of the steric hindrance for the nucleophilic substitution of cobalt(I) (14,15).…”