Nickel-catalysed decarbonylative borylation of aroyl fluorides
作者:Zhenhua Wang、Xiu Wang、Yasushi Nishihara
DOI:10.1039/c8cc08504h
日期:——
The first Ni(cod)2/PPh3 catalyst system has been established for decarbonylative borylation of aroylfluorides with bis(pinacolato)diboron. A wide range of functional groups in the substrates were well tolerated. The ease of access of the starting aroylfluorides indicates that these results might become an alternative to the existing decarbonylation events.
Palladium/Copper-Cocatalyzed Arylsilylation of Internal Alkynes with Acyl Fluorides and Silylboranes: Synthesis of Tetrasubstituted Alkenylsilanes by Three-Component Coupling Reaction
作者:Qiang Chen、Zhenyao Li、Yasushi Nishihara
DOI:10.1021/acs.orglett.1c04060
日期:2022.1.14
In this Letter, the palladium/copper-cocatalyzed arylsilylation of internal alkynes with acyl fluorides and silylboranes is described. This is the first example in which acyl fluorides have been utilized for the three-component coupling reaction via decarbonylation, yielding a variety of tetrasubstituted alkenylsilanes in moderate to good yields.
A phosphine-catalyzed acyl-group exchangereaction between carboxylic acids and an aroyl fluoride has been developed. A variety of acyl fluorides are directly obtained from carboxylic acids through a catalytic system composed of tricyclohexylphosphine (PCy3) and 2,6-difluorobenzoyl fluoride as a novel deoxyfluorination reagent.
Acyl fluorides are subjected to methoxylation with tris(2,4,6-trimethoxyphenyl)phosphine (TMPP) to afford the corresponding methyl esters in good to excellent yields. This transformation is featured by C(sp(2))-OMe bond cleavage under metal-free conditions. Unprecedented utilization of TMPP as a methoxylating agent realized the installation of an OMe group into the desired products.
Synthesis and inclusion ability of anthracene appended β-cyclodextrins: unexpected effect of triazole linker
A new fluorescent beta-cyclodextrin has been synthesized by coupling an anthracene moiety to the cyclic oligosaccharide via click chemistry. The influence of the triazole spacer was compared to the simple amino and amido linkers. While a sensing ability toward adamantan-1-ol was observed with the latter two spacers, the absence of inclusion capacity prevents the triazole modified cyclodextrin from showing any fluorescence variations. The difference in the binding behaviors studied by Isothermal Titration Calorimetry, UV-vis and fluorescence spectroscopies, was highlighted by the NOESY NMR spectra of the modified cyclodextrins: whereas a free cavity was observed for the amino and amido linkers, an important obstruction was obtained in the case of the triazole. (C) 2010 Elsevier Ltd. All rights reserved.