Substituent Effects on Aryltrifluoroborate Solvolysis in Water: Implications for Suzuki−Miyaura Coupling and the Design of Stable 18F-Labeled Aryltrifluoroborates for Use in PET Imaging
摘要:
Whereas electron withdrawing substituents retard the rate of aryltrifluoroborate solvolysis, electron-donating groups enhance it. Herein is presented a Hammett analysis of the solvolytic lability of aryltrifluoroborates where log(k(solv)) values correlate to sigma values with a rho value of approximately -1. This work provides a predictable rubric for tuning the reactivity of boron for several uses including F-18-labeled PET reagents and has mechanistic implications for ArBF3-enhanced ligandless metal-mediated cross coupling reactions with aryltrifluoroborates.
Substituent Effects on Aryltrifluoroborate Solvolysis in Water: Implications for Suzuki−Miyaura Coupling and the Design of Stable <sup>18</sup>F-Labeled Aryltrifluoroborates for Use in PET Imaging
作者:Richard Ting、Curtis W. Harwig、Justin Lo、Ying Li、Michael J. Adam、Thomas J. Ruth、David M. Perrin
DOI:10.1021/jo800681d
日期:2008.6.1
Whereas electron withdrawing substituents retard the rate of aryltrifluoroborate solvolysis, electron-donating groups enhance it. Herein is presented a Hammett analysis of the solvolytic lability of aryltrifluoroborates where log(k(solv)) values correlate to sigma values with a rho value of approximately -1. This work provides a predictable rubric for tuning the reactivity of boron for several uses including F-18-labeled PET reagents and has mechanistic implications for ArBF3-enhanced ligandless metal-mediated cross coupling reactions with aryltrifluoroborates.