Palladium-catalyzed borylation of aryl (pseudo)halides and its applications in biaryl synthesis

Abstract

A facile and efficient palladium-catalyzed borylation of aryl (pseudo)halides at room temperature has been developed. Arylboronic esters were expeditiously assembled in good yields and with a broad substrate scope and good functional group compatibility. This approach has been successfully applied to the one-pot two-step borylation/Suzuki–Miyaura cross-coupling reaction, providing a concise access to biaryl compounds from readily available aryl halides. Furthermore, a parallel synthesis of biaryl analogs is accomplished at room temperature using the strategy, which enhances the practical usefulness of this method.Electronic supplementary materialThe online version of this article (10.1186/s13065-018-0510-6) contains supplementary material, which is available to authorized users.

Recent Expedition in Pd‐ and Rh‐Catalyzed C(Ar)−B Bond Formations and Their Applications in Modern Organic Syntheses

“…Conducting the arene borylation at ambient reaction temperature is attractive to academic and process chemists. In 2018, Ji and Yi described the use of a Buchwald's precatalyst XPhos Pd G3 for borylation of aryl (pseudo)halides under room temperature conditions (Scheme 3a) [27] . A one‐pot two‐step preparation of biaryl compounds using this reaction protocol was also presented by adding another aryl halides for the Suzuki‐Miyaura coupling.…”

“…The synthesis of 2‐mesityl‐4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolane was successfully presented by several research groups using different catalyst systems (Scheme 4a) [30] . It is notable that even 2‐bromo‐1,3‐dimethoxybenzene could be used as coupling partner to afford the corresponding boronates in good yield (i. e. 75 % by Kuwano; [27] 67 % by Maumela [27] ). In 2021, Tran and de Vries reported the application of (allyl)PdCl‐XPhos complex (0.5 mol %) together with extra XPhos (0.5 mol %) for borylation of aryl iodides, bromides, and chlorides [31] .…”

“…It was suggested that the halogen exchange at the palladium species or an over stabilization of this palladium(II) intermediate may give beneficial effect in the catalytic cycle. Later, a Pd(dba) 2 /XPhos catalyst system was investigated by Nechaev in the solvent‐free borylation of aryl chlorides and one‐pot, two‐steps homocoupling [27] . Almost at the same time, Matsubara and Yorimitsu also disclosed the borylation of aryl chlorides with different diboron reagents (Scheme 11c) [62] .…”

Nickel-Catalyzed Ipso-Borylation of Silyloxyarenes via C–O Bond Activation

“…For example, borylations of pseudohalides and pivalates can be sensitive to strong bases like tert-butoxide, and thus rely on weaker Lewis bases to activate the diboron. 11,12 While less sensitive to base, carbamates still suffer from decreased reactivity regarding isolated aromatic systems as they take 48 h to afford appreciable yields of desired product. 13,14 Being the most stable, methyl ethers are tolerant to promotion by alkoxide bases, however, this class of transformations is not effective with isolated aromatic systems unless an ortho-directing group is present.…”

“…Attractive methods have also been described for the light-mediated and transition-metal-catalyzed reactions enabling the borylation of aryl halides and aryl C–H bonds . More recently, C–O electrophiles have been utilized as precursors to aryl boronic acids, although opportunities for improvement include avoiding easily hydrolyzed activating groups and providing improved reactivity with isolated aromatic ring substrates. − …”