Direct Application of Phenolic Salts to Nickel‐Catalyzed Cross‐Coupling Reactions with Aryl Grignard Reagents

Abstract

You're nickel'd pal! The first successful coupling reaction with the direct application of naphtholates as electrophiles (see scheme, X=halide) improves both the step economy and atom economy of cross‐coupling reactions whilst decreasing the cost of preparing complex scaffolds from readily available phenol derivatives.

Cross‐Coupling of Aryl/Alkenyl Ethers with Aryl Grignard Reagents through Nickel‐Catalyzed CO Activation

“…[b] Yield of isolated products. and OCF 3 , was a better leaving group than OMe (Table 3, entries [1][2][3][4][5][6][7][8][9]. The reaction of PhOCF 3 with pMe 2 NC 6 H 4 MgBr catalyzed by either I or II in toluene at 120 8C generated the cross-coupling products in 83 % yields (Table 3, entries 10 and 11).…”

“…[3,[5][6][7][8] For example, Dankwardt has reported a reaction of aryl methyl ethers with aryl Grignard reagents using [(Cy 3 P) 2 [5d, e] Very recently, Shi and co-workers have reported a Kumada-type coupling of magnesium naphtholates as electrophiles. [9] Ackermann and Mulzer have also reported the CÀOH bond functionalization of phenols through the activation of a CÀO and a CÀH bond catalyzed by ruthenium. [10] Although significant progress has been achieved, the substrate scope for these reactions is still limited and the development of more efficient catalytic systems is also desirable.…”

Nickel-Catalyzed Cross-Couplings Involving Carbon−Oxygen Bonds

“…Shi and coworkers recently described the unprecedented cross-coupling of 2-naphthol derivatives 286. In this transformation, 2-naphthol derivatives were treated sequentially with methyl magnesium bromide and an aryl Grignard reagent in the presence of Ni II F 2 and PCy 3 at 120 °C to deliver arylated products (Scheme 161).…”

Metal-Catalyzed Carboxylation of Organic (Pseudo)halides with CO2

“…Unfortunately, the reaction of both aryl and benzyl esters remained restricted to extended π-systems, a recurrent limitation encountered in a myriad of C–O bond-cleavage scenarios. 42 This limitation could partially be tackled by the use of hemilabile directing groups on the ester motif, 43 thus accelerating the rate of oxidative addition while opening up coordination sites on the Ni center, ultimately facilitating the corresponding CO 2 insertion into the targeted C–O bond. According to previous studies on Ni-catalyzed reductive carboxylations, a catalytic cycle involving SET-processes mediated by Mn to generate Ni(I) species prior CO 2 insertion into the C–Ni bond was proposed.…”