Direct Hiyama Cross-Coupling of (Hetero)arylsilanes with C(sp²)–H Bonds Enabled by Cobalt Catalysis

Abstract

We report a chelation-assisted C−H arylation of various indoles with sterically and electronically diverse (hetero)arylsilanes enabled by cost-effective Cp*-free cobalt catalysis. Key to the success of this strategy is the judicious choice of copper(II) fluoride as a bifunctional sliane activator and catalyst reoxidant. This methodology features a broad substrate scope and good functional group compatibility. The synthetic versatility of this protocol has been highlighted by the gram-scale synthesis and late-stage diversification of biologically active molecules.

Copper-Promoted Hiyama Cross-Coupling of Arylsilanes With Thiuram Reagents: A Facile Synthesis of Aryl Dithiocarbamates

“…Considering the experimental evidence as well the previous reports ( Lu et al, 2020 ; Dong et al, 2017 ; Luo et al, 2020 ; Hao et al, 2020 ; Lai et al, 2019b ), a plausible reaction mechanism was tentatively proposed and described in Scheme 4 . Firstly, the coordination of 1, 10-phenanthroline with copper salts to produce the copper complex A.…”

“…Generally, organosilicon reagents exhibit some remarkable advantages such as non-toxicity, high stability, good tolerance toward various functional groups and natural abundance of silicon. In the overpast several decades, significant advances on transition-metal-catalyzed Hiyama cross-coupling have been achieved ( Nareddy et al, 2017 ; Nareddy et al, 2018 ; González et al, 2019 ; Han et al, 2019 ; Zhang et al, 2019 ; Idris and Lee, 2020 ; Lu et al, 2020 ; Wu et al, 2021 ), nevertheless, the diverse applications of this methodology are still less explored and worthy of in-depth exploration under the concept of green chemistry.…”

Cu-Catalyzed Arylation of Bromo-Difluoro-Acetamides by Aryl Boronic Acids, Aryl Trialkoxysilanes and Dimethyl-Aryl-Sulfonium Salts: New Entries to Aromatic Amides

“…All used boronic acids 2 and some aryl trialkoxysilanes 3 are commercially available and were purchased from appropriate vendors. 2-Bromo-2,2-difluoroacetamides [ 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 ], 1, 2-iodo-2,2-difluoroacetamides [ 54 ], aryl trialkoxysilanes 3 [ 58 , 59 , 60 , 61 , 62 , 63 , 64 ], sulfonium salts 4 [ 65 , 66 , 67 ], and calixarenes L1 , L2 [ 68 , 69 ] are known compounds in the literature and were prepared according to the known literature, and the spectral data are identical with the corresponding literature. Copies 1 H and 13 C-NMR spectra are placed in Supplementary Materials .…”

On the application of 3d metals for C–H activation toward bioactive compounds: The key step for the synthesis of silver bullets

“…Beyond the above-cited cobalt-Cp* examples, other classes of cobalt catalysts can also be used to affect C-H activation in different substrates. A good example is the use of chelated cobalt(III) catalysts, such as [Co(acac) 3 ], as recently mentioned by Lu, Loh and co-workers [202]. In this work, the catalyst was used to mediate a C-H arylation at the C-2 position of N-(2pyrimidyl)pyrrole derivatives (Scheme 40A).…”