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Ni-Catalyzed Cross-Coupling of Heteroaryltrifluoroborates with Unactivated Alkyl Halides

By: Aaron Thornton, Chemfiles Volume 11 Article 1

Recently the lab of Professor Gary Molander disclosed a method for the effective cross-coupling of air and moisture stable heteroaryltrifluoroborates with unactivated alkyl halides.1While previous methods for this same transformation have been developed, still today a number of shortcomings remain. Most notable is the need for excess organoboron coupling partner, and the limited scope of organoboron reagents that can be used for this transformation (generally restricted to aryl boronic acids only). To address these issues, Molander has taken advantage of the increased stability of organotrifluoroborates as well as the increased reactivity of Ni catalysts. Under the optimized conditions a range of heteroaryltrifluoroborates can be coupled efficiently with both alkyl bromides and iodides (Table 1).


Table 1: Cross-coupling of 2-benzofuranyl- and 4-pyridinyltrifluoroborates with various alkyl halides.

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Materials

     

References

  1. Molander, G. A.; Argintaru, O. A.; Aron, I.; Dreher, S. D. Org. Lett. 2010, 24, 5783.

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