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Abstract Understanding the electronic structures of high‐valent metal complexes aids the advancement of metal‐catalyzed cross coupling methodologies. A prototypical complex with formally high valency is [Cu(CF3)4]−(1), which has a formal Cu(III) oxidation state but whose physical analysis has led some to a Cu(I) assignment in an inverted ligand field model. Recent examinations of1by X‐ray spectroscopies have led previous authors to contradictory conclusions, motivating the re‐examination of its X‐ray absorption profile here by a complementary method, resonant diffraction anomalous fine structure (DAFS). From analysis of DAFS measurements for a series of seven mononuclear Cu complexes including1, here it is shown that there is a systematic trifluoromethyl effect on X‐ray absorption that blue shifts the resonant Cu K‐edge energy by 2–3 eV per CF3, completely accounting for observed changes in DAFS profiles between formally Cu(III) complexes like1and formally Cu(I) complexes like (Ph3P)3CuCF3(3). Thus, in agreement with the inverted ligand field model, the data presented herein imply that1is best described as containing a Cu(I) ion with dncount approaching 10.
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Synthesis of Bisheteroarylalkanes by Heteroarylboration: Development and Application of a Pyridylidene–Copper Complex
Abstract The development of pyridylidene‐Cu‐complexes and their application in Cu/Pd‐catalyzed heteroarylboration of alkenylheteroarenes is reported. The significance of 1,1′‐heteroarylalkanes as building blocks for drug discovery, as well as the straightforward and modular sequence to prepare the pyridylidene‐Cu‐complexes, makes this catalyst and it applications attractive for chemical synthesis. Furthermore, chiral variants of the pyridylidene‐Cu‐complexes have been prepared and utilized in the enantioselective arylboration of E‐alkenes, further demonstrating the value and potential of this class of catalysts.
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- Award ID(s):
- 1554760
- PAR ID:
- 10089195
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie International Edition
- Volume:
- 58
- Issue:
- 18
- ISSN:
- 1433-7851
- Page Range / eLocation ID:
- p. 6048-6052
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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