(carbene)CuF Complexes Featuring Bulky Arduengo-Type, Ring-Expanded, and Cyclic (Alkyl)(amino)carbenes: Applications in Catalytic Aldehyde Allylation

Abstract

Five examples of two-coordinate copper(I) fluoride complexes stabilized by five-, six-, and sevenmembered-ring N-heterocyclic carbenes or a cyclic (alkyl)-(amino)carbene have been prepared, structurally characterized, and employed in the catalytic allylation of octanal. The very bulky trityl-based carbene ITr affords the most active catalytic system. Mechanistic studies have led to the isolation of (ITr)Cu(CH 2 CHCH 2 ) and [{(6-Mes)Cu} 2 (μ-OEt)][SiF 5 ], which along with the fluorosilane (EtO) 3 SiF are of relevance to the catalytic cycle.

Substituent Effect on the Circularly Polarized Luminescence of C1‐Symmetric Carbene‐Copper(I) Complexes

“…The complexes with larger halides (X=Br, I) were obtained by coordination of the free carbenes with the corresponding copper halide salts [13] . The copper fluoride complexes were obtained by protonation of the copper mesityl with HF‐NEt 3 [14] . Single crystals were grown from THF/pentane.…”

(2-Fluoroallyl)boration of Ketones with (2-Fluoroallyl)boronates

“…A remarkable regioselectivity change was observed when a presynthesized hydrofluoride complex (IPr)­CuF·HF was used as the catalyst. , E -Isomeric alcohol ( E )- 4a was obtained in almost a quantitative yield (entry 8). The chlorinated complex (IPr Cl )­CuF·HF again was several times more active than (IPr)­CuF·HF (entry 10 vs entry 9).…”

Recent Advances in the Domain of Cyclic (Alkyl)(Amino) Carbenes

“…Recently, Whittelsey et al reported a cAACÀ Cu(I)F complex which catalyzes aldehyde allylation, though the yield of the reaction is low. [49] It is interesting to note that just like cAACsÀ Au(I) complexes, cAACs supported Hg(II)-complexes also catalyze intermolecular hydroamination reactions of alkynes. The very first hydroamination reaction of alkynes catalyzed by cAACÀ Hg(II) complex was reported by Singh et al in 2018.…”

“…Recently, Whittelsey et al. reported a cAAC−Cu(I)F complex which catalyzes aldehyde allylation, though the yield of the reaction is low [49] …”