29800-84-8Relevant articles and documents
Base-Promoted Oxidative C(sp3)–S Bond Cross-Coupling of Inactive Fluorenes and Thiols for the Synthesis of 9-Monothiolated Fluorenes
Liu, Yafeng,Yuan, Xinglong,Su, Kexin,Tian, Yuan,Chen, Baohua
supporting information, p. 1649 - 1652 (2019/01/30)
The highly efficient and selective C(sp3)–S bond cross-coupling method for the synthesis of 9-thiolated fluorenes through a direct thiolation at 9-C(sp3)–H of fluorenes with thiols is described. This reaction occurs at ambient conditions and shows good tolerance of functional groups including arylthiols and alkylthiols. A wide range of products is obtained in moderate to good yields. Besides, the reaction of benzothiophenol and fluorine generates unexpected 9-benzylidene-9H-fluorene by eliminating hydrogen sulfide.
Broensted Correlations for Electron Transfer from Carbanions to Halomethyl Phenyl Sulfone and 1,1-Dinitroalkane-Type Acceptors
Bordwell, Frederick G.,Clemens, Anthony H.
, p. 2510 - 2516 (2007/10/02)
9-Substituted fluorenyl carbanions, 9-G-Fl(1-), with G = Ar or Me, have been dimerized to (9-G-Fl)2 by reaction in Me2SO solution with PhSO2CH2X and R2C(NO2)X electron acceptors.Rate measurements revealed the following electron-accepting abilities: c-C6H10(NO2)2 > Me2C(NO2)2 > PhSO2CH2Br, PhSO2CH2I > c-C6H10(NO2)CN > c-C6H10(NO2)SO2C7H7 > Me2C(NO2)SO2C7H7 > PhSO2CH2Cl.The rate-limiting step in these reactions is electron transfer from 9-G-Fl(1-) to the electron acceptor.Plots of log k vs. pKa of 9-G-FlH are linear with a slope near unity for all seven electron acceptors studied.We conclude that a Broensted β of unity is characteristic of electron transfer from carbanions to electron acceptors in Me2SO solution.This is interpreted to mean that the changes in ΔG0 brought about by changes in the basicity of the carbanion are matched by changes in ΔG(excit.), which correspond to the difference in the energy gap between the HOMO of the donor and the LUMO of the acceptor.
