- Base-Free Pd-Catalyzed C?Cl Borylation of Fluorinated Aryl Chlorides
-
Catalytic C?X borylation of aryl halides containing two ortho-fluorines has been found to be challenging, as most previous methods require stoichiometric amounts of base and the polyfluorinated aryl boronates suffer from protodeboronation, which is accele
- Budiman, Yudha P.,Lorenzen, Sabine,Liu, Zhiqiang,Radius, Udo,Marder, Todd B.
-
-
Read Online
- Protodeboronation of (Hetero)Arylboronic Esters: Direct versus Prehydrolytic Pathways and Self-/Auto-Catalysis
-
The kinetics and mechanism of the base-catalyzed hydrolysis (ArB(OR)2→ ArB(OH)2) and protodeboronation (ArB(OR)2→ ArH) of a series of boronic esters, encompassing eight different polyols and 10 polyfluoroaryl and heteroaryl moieties, have been investigated by in situ and stopped-flow NMR spectroscopy (19F,1H, and11B), pH-rate dependence, isotope entrainment,2H KIEs, and KS-DFT computations. The study reveals the phenomenological stability of boronic esters under basic aqueous-organic conditions to be highly nuanced. In contrast to common assumption, esterification does not necessarily impart greater stability compared to the corresponding boronic acid. Moreover, hydrolysis of the ester to the boronic acid can be a dominant component of the overall protodeboronation process, augmented by self-, auto-, and oxidative (phenolic) catalysis when the pH is close to the pKaof the boronic acid/ester.
- Hayes, Hannah L. D.,Wei, Ran,Assante, Michele,Geogheghan, Katherine J.,Jin, Na,Tomasi, Simone,Noonan, Gary,Leach, Andrew G.,Lloyd-Jones, Guy C.
-
p. 14814 - 14826
(2021/09/13)
-
- Transition Metal Catalyst-Free, Base-Promoted 1,2-Additions of Polyfluorophenylboronates to Aldehydes and Ketones
-
A novel protocol for the transition metal-free 1,2-addition of polyfluoroaryl boronate esters to aldehydes and ketones is reported, which provides secondary alcohols, tertiary alcohols, and ketones. Control experiments and DFT calculations indicate that both the ortho-F substituents on the polyfluorophenyl boronates and the counterion K+ in the carbonate base are critical. The distinguishing features of this procedure include the employment of commercially available starting materials and the broad scope of the reaction with a wide variety of carbonyl compounds giving moderate to excellent yields. Intriguing structural features involving O?H???O and O?H???N hydrogen bonding, as well as arene-perfluoroarene interactions, in this series of racemic polyfluoroaryl carbinols have also been addressed.
- Budiman, Yudha P.,Friedrich, Alexandra,Kole, Goutam Kumar,Liu, Zhiqiang,Luo, Xiaoling,Marder, Todd B.,Radius, Udo,Tian, Ya-Ming,Westcott, Stephen A.
-
supporting information
p. 16529 - 16538
(2021/06/23)
-
- Copper-Catalyzed Oxidative Cross-Coupling of Electron-Deficient Polyfluorophenylboronate Esters with Terminal Alkynes
-
We report herein a mild procedure for the copper-catalyzed oxidative cross-coupling of electron-deficient polyfluorophenylboronate esters with terminal alkynes. This method displays good functional group tolerance and broad substrate scope, generating cro
- Liu, Zhiqiang,Budiman, Yudha P.,Tian, Ya-Ming,Friedrich, Alexandra,Huang, Mingming,Westcott, Stephen A.,Radius, Udo,Marder, Todd B.
-
supporting information
p. 17267 - 17274
(2020/12/01)
-
- Fluorine-controlled C-H borylation of arenes catalyzed by a PSiN-pincer platinum complex
-
An efficient, regioselective synthesis of fluorine-substituted arylboronic esters was achieved through fluorine-controlled C-H borylation of arenes with diboron catalyzed by a PSiN-platinum complex. The promising utility of the PSiN-platinum catalyst and its unique regioselectivity were demonstrated for the first time, which would complement the well-developed Ir-catalyzed C-H borylation.
- Takaya, Jun,Ito, Shisei,Nomoto, Hironori,Saito, Narumasa,Kirai, Naohiro,Iwasawa, Nobuharu
-
supporting information
p. 17662 - 17665
(2015/12/18)
-