90172-21-7Relevant academic research and scientific papers
Borane-catalyzed C(sp3)-F bond arylation and esterification enabled by transborylation
Willcox, Dominic R.,Nichol, Gary S.,Thomas, Stephen P.
, p. 3190 - 3197 (2021/04/06)
The activation and functionalization of carbon- fluorine bonds represent a significant synthetic challenge, given the high thermodynamic barrier to C-F bond cleavage. Stoichiometric hydridoborane-mediated C-F functionalization has recently emerged, but is yet to be rendered catalytic. Herein, the borane-catalyzed coupling of alkyl fluorides with arenes (carbon-carbon bond formation) and carboxylic acids (carbon-oxygen bond formation) has been developed using transborylation reactions to achieve catalytic turnover. Successful C-C and C-O coupling across a variety of structurally and electronically differentiated arenes and carboxylic acids was achieved using 9-borabicyclo[3.3.1]nonane (H-B-9-BBN) as the catalyst and pinacolborane (HBpin), with broad functional group tolerance. Experimental and computational studies suggest a mechanistic dichotomy for the carbon-carbon and carbon-oxygen coupling reactions. B-F transborylation (B-F/B-H metathesis) between F-B-9-BBN and HBpin enabled catalytic turnover for carbon-carbon bond formation, whereas direct exchange between the alkyl fluoride and acyloxyboronic ester (C-F/B-O metathesis) was proposed for carbon-oxygen coupling, where H-B-9-BBN catalyzed the dehydrocoupling of the carboxylic acid with HBpin.
Copper-catalyzed oxidative esterification of unactivated C(sp3)-H bonds with carboxylic acids via cross dehydrogenative coupling
Zhou, Jiadi,Jin, Can,Li, Xiaohan,Su, Weike
, p. 7232 - 7236 (2015/03/03)
An effective copper-catalyzed esterification of unactivated (non-benzylic and allylic) C(sp3)-H bonds of hydrocarbons with Selectfluor as an oxidant has been developed. This reaction could provide a direct, new and useful strategy for the synthesis of esters and alkyl alcohols by ester hydrolysis.
An efficient method for the preparation of tertiary esters by palladium-catalyzed alkoxycarbonylation of aryl bromides
Xin, Zhuo,Gogsig, Thomas M.,Lindhardt, Anders T.,Skrydstrup, Troels
supporting information; experimental part, p. 284 - 287 (2012/02/16)
The palladium-catalyzed alkoxycarbonylation of aryl bromides is described for the efficient preparation of tertiary esters. The protocol proved compatible with a wide variety of functionalized (hetero)aromatic bromides, as well as several different sterically hindered tertiary alcohols, affording the alkoxycarbonylated products in high yields. Finally, the formation of aromatic trityl esters is discussed.
p-Fluorobenzoyl Chloride for Characterization of Active Hydrogen Functional Groups by Fluorine-19 Nuclear Magnetic Resonance Spectrometry
Spratt, M. P.,Dorn, H. C.
, p. 2038 - 2043 (2007/10/02)
The base-catalyzed reactions of p-fluorobenzoyl chloride provide a convenient method for (19)F NMR analysis of alcohols, phenols, carboxylic acids, amines, and thiols.The (19)F chemical shift and yield data for p-fluorobenzoyl derivatives for nearly 100 compounds are presented.The yield data for these p-fluorobenzoyl derivatives suggest a simple, and in many cases, quantitative method for introducing a fluorine tagging group.The (19)F chemical shifts indicate a wide chemical shift range (ca. 10 ppm) for a large number of compounds.Furthermore, most chemical classes (e.g., phenols, alcohols, etc.) have fairly well resolved chemical shift regions.
