Suzuki−Miyaura Cross-Coupling Reactions of Benzyl Halides with Potassium Aryltrifluoroborates

Abstract

[reaction: see text] The palladium-catalyzed cross-coupling of potassium aryltrifluoroborates with benzylic halides occurs in good yield with high functional group tolerance. The increased stability of potassium aryltrifluoroborates compared to other boron coupling partners makes this an effective route to functionalized methylene-linked biaryl systems.

Insights into the Role of New Palladium Pincer Complexes as Robust and Recyclable Precatalysts for Suzuki–Miyaura Couplings in Neat Water

“…Diethylene glycol dimethyl ether was used as internal standard. Another version of this coupling was performed using benzyl halides and trifluoroborates, [19] but in this procedure the lack of commercial availability of the nucleophilic reagents is the principal drawback. Taking into account our own experience in the preparation of diarylmethanes by coupling of benzyl bromides and arylboronic acids, [7b] and considering that this procedure has been scarcely studied, [20] the catalytic activity of pincers 2 and 3 was evaluated in this reaction.…”

Recent Advances in the Synthesis of Triarylmethanes by Transition Metal Catalysis

“…The first example of this type of reaction in the context of triarylmethane synthesis was reported by Molander, who described the Pd-catalyzed reaction of benzhydryl bromide with potassium 4-methoxyphenyltrifluoroborate to afford the desired triarylmethane product (Scheme 1a). 11 However, the benzhydryl bromide homocoupling byproduct was also observed in a 1:1.5 ratio, favoring the desired product. In 2009, Adrio and Carretero discovered that Grignard reagents were successful coupling partners for the same electrophile, such that the reaction of benzhydryl bromide with 4-fluorophenyl-magnesium bromide gave the corresponding triarylmethane in excellent yield employing a combination of Pd(MeCN) 2 Cl 2 and Xantphos as the catalyst (Scheme 1b).…”

Organotrifluoroborates: Protected Boronic Acids That Expand the Versatility of the Suzuki Coupling Reaction

“…By contrast, conditions have been developed whereby a variety of aryltrifluoroborates can be coupled on an equimolar basis with benzyl bromide, affording the desired product in excellent yields ( Figure 3). 22 In addition to aryltrifluoroborates, alkenyltrifluoroborates are also suitable substrates for cross-coupling processes, providing a complementary route to conjugated, unsaturated arenes. 23 Under the reaction conditions developed, a variety of functional groups are tolerated within both the alkenyl trifluoroborate and the aryl halide ( Figure 4).…”