TY  - JOUR
A1  - Zhang, Xiaolei
A1  - Friedrich, Alexandra
A1  - Marder, Todd B.
T1  - Copper-Catalyzed Borylation of Acyl Chlorides with an Alkoxy Diboron Reagent: A Facile Route to Acylboron Compounds
JF  - Chemistry—A European Journal
N2  - Herein, the copper-catalyzed borylation of readily available acyl chlorides with bis(pinacolato)diboron, (B\(_{2}\)pin\(_{2}\)) or bis(neopentane glycolato)diboron (B\(_{2}\)neop\(_{2}\)) is reported, which provides stable potassium acyltrifluoroborates (KATs) in good yields from the acylboronate esters. A variety of functional groups are tolerated under the mild reaction conditions (room temperature) and substrates containing different carbon-skeletons, such as aryl, heteroaryl and primary, secondary, tertiary alkyl are applicable. Acyl N-methyliminodiacetic acid (MIDA) boronates can also been accessed by modification of the workup procedures. This process is scalable and also amenable to the late-stage conversion of carboxylic acid-containing drugs into their acylboron analogues, which have been challenging to prepare previously. A catalytic mechanism is proposed based on in situ monitoring of the reaction between p-toluoyl chloride and an NHC-copper(I) boryl complex as well as the isolation of an unusual lithium acylBpinOBpin compound as a key intermediate.
KW  - boronate
KW  - catalysis
KW  - borylation
KW  - carbonyl
KW  - copper
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-318318
VL  - 28
IS  - 42
ER  - 
TY  - JOUR
A1  - Ramler, Jacqueline
A1  - Schwarzmann, Johannes
A1  - Stoy, Andreas
A1  - Lichtenberg, Crispin
T1  - Two Faces of the Bi−O Bond: Photochemically and Thermally Induced Dehydrocoupling for Si−O Bond Formation
JF  - European Journal of Inorganic Chemistry
N2  - The diorgano(bismuth)alcoholate [Bi((C\(_{6}\)H\(_{4}\)CH\(_{2}\))\(_{2}\)S)OPh] (1-OPh) has been synthesized and fully characterized. Stoichiometric reactions, UV/Vis spectroscopy, and (TD-)DFT calculations suggest its susceptibility to homolytic and heterolytic Bi−O bond cleavage under given reaction conditions. Using the dehydrocoupling of silanes with either TEMPO or phenol as model reactions, the catalytic competency of 1-OPh has been investigated (TEMPO=(tetramethyl-piperidin-1-yl)-oxyl). Different reaction pathways can deliberately be addressed by applying photochemical or thermal reaction conditions and by choosing radical or closed-shell substrates (TEMPO vs. phenol). Applied analytical techniques include NMR, UV/Vis, and EPR spectroscopy, mass spectrometry, single-crystal X-ray diffraction analysis, and (TD)-DFT calculations.
KW  - Bismuth
KW  - dehydrocoupling
KW  - radical reactions
KW  - chalcogens
KW  - catalysis
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-257428
VL  - 2022
IS  - 7
ER  - 
TY  - JOUR
A1  - Lichtenberg, Crispin
T1  - Main‐Group Metal Complexes in Selective Bond Formations Through Radical Pathways
JF  - Chemistry – A European Journal
N2  - Recent years have witnessed remarkable advances in radical reactions involving main‐group metal complexes. This includes the isolation and detailed characterization of main‐group metal radical compounds, but also the generation of highly reactive persistent or transient radical species. A rich arsenal of methods has been established that allows control over and exploitation of their unusual reactivity patterns. Thus, main‐group metal compounds have entered the field of selective bond formations in controlled radical reactions. Transformations that used to be the domain of late transition‐metal compounds have been realized, and unusual selectivities, high activities, as well as remarkable functional‐group tolerances have been reported. Recent findings demonstrate the potential of main‐group metal compounds to become standard tools of synthetic chemistry, catalysis, and materials science, when operating through radical pathways.
KW  - bond formation
KW  - catalysis
KW  - main-group metals
KW  - organic and inorganic synthesis
KW  - radicals
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-214758
VL  - 26
IS  - 44
SP  - 9674
EP  - 9687
ER  -