Iodosylbenzene

Reaction of the tricopper(I)-dinitrogen tris(β-diketiminate) cyclophane, Cu(N)L, with O-atom-transfer reagents or elemental Se affords the oxido-bridged tricopper complex Cu(μ-O)L (2) or the corresponding Cu(μ-Se)L (4), respectively. For 2 and 4, incorporation of the bridging chalcogen donor was supported by electrospray ionization mass spectrometry and K-edge X-ray absorption spectroscopy (XAS) data. Cu L-edge X-ray absorption data quantify 49.5% Cu 3d character in the lowest unoccupied molecular orbital of 2, with Cu 3d participation decreasing to 33.0% in 4 and 40.8% in the related sulfide cluster Cu(μ-S)L (3). Multiedge XAS and UV/visible/near-IR spectra are employed to benchmark density functional theory calculations, which describe the copper-chalcogen interactions as highly covalent across the series of [Cu(μ-E)] clusters. This result highlights that the metal-ligand covalency is not reserved for more formally oxidized metal centers (i.e., Cu + O vs Cu + O) but rather is a significant contributor even at more typical ligand-field cases (i.e., Cu + E). This bonding is reminiscent of that observed in p-block elements rather than in early-transition-metal complexes.

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“…The ligand H 3 L and tricopper complex 1 were synthesized as previously reported. Iodosobenzene was synthesized as described elsewhere …”

Section: Methodsmentioning

confidence: 99%

Chalcogen Impact on Covalency within Molecular [Cu₃(μ₃-E)]³⁺ Clusters (E = O, S, Se): A Synthetic, Spectroscopic, and Computational Study

et al. 2018

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“…Thus, after reaction of 1a with 8 (1 equiv) and AcOH (3 equiv) in MeCN for 10 min (same as Table , entry 11), the 2a obtained can be used directly for further transformations without purification. Thus, treatment of TsOH·H 2 O, CF 3 CO 2 H, and NaOH resulted in the formation of hydroxy(tosyloxy)iodobenzene ( 11 ), bis(trifluoroacetoxy)iodobenzene ( 12 ), and iodosylbenzene ( 13 ) in fairly good yields; all of these compounds are important reagents in current synthetic organic chemistry . Furthermore, reaction with dimedone and p -nitrobenzenesulfonamide under basic conditions afforded iodonium ylide 14 and imino-λ 3 -iodane 15 in good to high yields …”

Section: Resultsmentioning

confidence: 99%

Safer Synthesis of (Diacetoxyiodo)arenes Using Sodium Hypochlorite Pentahydrate

et al. 2018

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A practical method for the preparation of (diacetoxyiodo)arene ArI(OAc)2 is described. The use of commercially available sodium hypochlorite pentahydrate (NaClO·5H2O) enabled safe, rapid, and inexpensive oxidation of iodoarenes with electron-withdrawing and -donating substituents. The method allows tandem divergent access to synthetically useful organo-λ3-iodanes such as hydroxyl(tosyloxy)iodobenzene, iodosylbenzene, iodonium ylide, etc.

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“…Best yields resulted with excess acceptor alcohol (5 equiv), perhaps because of a need to activate the insoluble, oligomeric iodosobenzene oxidant. 45 A final example in the glucal series (entry 11) demonstrated installation of a diglyme-type linker with a primary halide functionality in product 17fk . Electrophile-containing anomeric groups are of utility for attachment of carbohydrate units to molecules of biological and medicinal interest.…”

Section: Resultsmentioning

confidence: 99%

“…Several examples from our preliminary report (entries 8–10) further demonstrate the reaction scope for glucal substrates, including direct access to disaccharide 17fj . Best yields resulted with excess acceptor alcohol (5 equiv), perhaps because of a need to activate the insoluble, oligomeric iodosobenzene oxidant . A final example in the glucal series (entry 11) demonstrated installation of a diglyme-type linker with a primary halide functionality in product 17fk .…”

Section: Resultsmentioning

confidence: 99%

Glycal Metallanitrenes for 2-Amino Sugar Synthesis: Amidoglycosylation of Gulal-, Allal-, Glucal-, and Galactal 3-Carbamates

et al. 2018

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The rhodium(II)-catalyzed oxidative cyclization of glycal 3-carbamates with in situ incorporation of an alcohol nucleophile at the anomeric position provides access to a range of 2-amino sugars having 1,2-trans-2,3-cis stereochemistry, a structural motif present in compounds of medicinal and biological significance such as the streptothricin group of antibiotics and the Chitinase inhibitor allosamidin. All of the diastereomeric d-glycal 3-carbamates have been investigated, revealing significant differences in anomeric stereoselectivity depending on substrate stereochemistry and protecting groups. In addition, some substrates were prone to forming C3-oxidized dihydropyranone byproducts under the reaction conditions. Allal- and gulal 3-carbamates provided uniformly high stereo- and chemoselectivity, while for glucal substrates, acyclic, electron-withdrawing protecting groups at the 4 O and 6 O positions were required. Galactal 3-carbamates have been the most challenging substrates; formation of their amidoglycosylation products is most effective with an electron-withdrawing 6 O-Ts substituent and a sterically demanding 4 O-TBS group. These results suggest a mechanism whereby conformational and electronic factors determine the partitioning of an intermediate acyl nitrenoid between alkene addition, leading to amidoglycosylation, and C3-H insertion, providing the dihydropyranone byproduct. Along the amidoglycosylation pathway, high anomeric selectivity results when a glycosyl aziridine intermediate is favored over an aziridine-opened oxocarbenium donor.

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Iodosylbenzene

Cited by 6 publications

References 199 publications

Chalcogen Impact on Covalency within Molecular [Cu₃(μ₃-E)]³⁺ Clusters (E = O, S, Se): A Synthetic, Spectroscopic, and Computational Study

Chalcogen Impact on Covalency within Molecular [Cu₃(μ₃-E)]³⁺ Clusters (E = O, S, Se): A Synthetic, Spectroscopic, and Computational Study

Safer Synthesis of (Diacetoxyiodo)arenes Using Sodium Hypochlorite Pentahydrate

Glycal Metallanitrenes for 2-Amino Sugar Synthesis: Amidoglycosylation of Gulal-, Allal-, Glucal-, and Galactal 3-Carbamates

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Iodosylbenzene

Cited by 6 publications

References 199 publications

Chalcogen Impact on Covalency within Molecular [Cu3(μ3-E)]3+ Clusters (E = O, S, Se): A Synthetic, Spectroscopic, and Computational Study

Chalcogen Impact on Covalency within Molecular [Cu3(μ3-E)]3+ Clusters (E = O, S, Se): A Synthetic, Spectroscopic, and Computational Study

Safer Synthesis of (Diacetoxyiodo)arenes Using Sodium Hypochlorite Pentahydrate

Glycal Metallanitrenes for 2-Amino Sugar Synthesis: Amidoglycosylation of Gulal-, Allal-, Glucal-, and Galactal 3-Carbamates

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Product

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Chalcogen Impact on Covalency within Molecular [Cu₃(μ₃-E)]³⁺ Clusters (E = O, S, Se): A Synthetic, Spectroscopic, and Computational Study

Chalcogen Impact on Covalency within Molecular [Cu₃(μ₃-E)]³⁺ Clusters (E = O, S, Se): A Synthetic, Spectroscopic, and Computational Study