Abstract
We newly developed lithium methyltriolborate as an air-stable white solid that is convenient to handle. The good performance of this triolborate for metal-catalyzed bond-forming reactions was demonstrated in palladium-catalyzed cross-coupling reactions with haloarenes. Cross-coupling reaction of [MeB(OCH2)3CCH3]Li with aryl halides occurred in the presence of Pd(OAc)2/RuPhos complex in refluxing MeOH/H2O and the absence of bases.
Highlights
Over the past three decades, it has become increasingly clear that organoboron compounds are valuable reagents capable of undergoing many catalytic C-C bond formations in organic synthesis [1,2,3,4,5,6].Boronic acids are convenient reagents that are generally thermally stable and are inert to water and oxygen, and it is easy to remove the inorganic by-products from the reaction mixture, making the reactions suitable for industrial processes
Since the first report in 1986 of the cross-coupling reaction between alkylboron reagents and aryl and alkenyl halides in the presence of a palladium catalyst and a base [7], B-alkyl cross-coupling has been frequently used in organic synthesis
We describe lithium methyltriolborate that is exceptionally stable in air and water
Summary
Over the past three decades, it has become increasingly clear that organoboron compounds are valuable reagents capable of undergoing many catalytic C-C bond formations in organic synthesis [1,2,3,4,5,6]. Since the first report in 1986 of the cross-coupling reaction between alkylboron reagents and aryl and alkenyl halides in the presence of a palladium catalyst and a base [7], B-alkyl cross-coupling has been frequently used in organic synthesis. Boronic acids are sometimes difficult to purify due to the lack of crystallization or the formation of trimeric cyclic anhydrides (boroxines). We have developed aryltriolborates [ArB(OCH2)3CCH3]M (M = Li, Na, K, and NBu4), that have good stability in air and water and high solubility in organic solvents and that undergo very smooth transmetalation to various transition metal complexes [29,30]. We demonstrate the high transmetalation efficiency of triolborate in palladium-catalyzed C-C bond-forming reaction
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have