Thermal stability of N-heterocycle-stabilized iodanes – a systematic investigation

• Andreas Boelke,
• Yulia A. Vlasenko,
• Mekhman S. Yusubov,
• Boris J. Nachtsheim and
• Pavel S. Postnikov

Beilstein J. Org. Chem. 2019, 15, 2311–2318, doi:10.3762/bjoc.15.223

• high Tpeak but also higher ΔHdec values for the latter ones. NHIs bearing N-heterocycles with a high N/C-ratio such as triazoles show among the lowest Tpeak and the highest ΔHdec values. A comparison of NHIs with known (pseudo)cyclic benziodoxolones is made and we further correlated their thermal

• of group-transfer reactions. Prominent examples include ethynyl benziodoxolones (EBX, L1 = alkyne) [12], the Zhdankin reagent azidobenziodoxole (ABX, L1 = N3) [13], cyanobenziodoxole (CBX, L1 = CN) [14] or Togni’s reagent (L1 = CF3) [15]. Even though the transferable ligand (L1) has been varied

• diaryliodonium salts 18 and 19 show a significantly decreased ΔHdec from 72.9 kJ/mol to 10.2 kJ/mol for benziodoxolones 1 and 18 and from 116.3 kJ/mol to 23.4 kJ/mol for the triazole derivatives 2 and 19. The same trend of a higher thermal stability and lower ΔHdec for diaryliodonium salts compared the their

Hypervalent organoiodine compounds: from reagents to valuable building blocks in synthesis

• Gwendal Grelier,
• Benjamin Darses and
• Philippe Dauban

Beilstein J. Org. Chem. 2018, 14, 1508–1528, doi:10.3762/bjoc.14.128

• ]. Review Tandem additions λ5-Iodanes such as the Dess–Martin periodinane or IBX [26], and λ3-iodanes such as benziodoxolones [27], are versatile reagents in organic synthesis. These are often used, respectively, for the oxidation of alcohols or carbonyl compounds, and in atom-transfer reactions. These

• reagents: CF3-benziodoxolone (Togni’s reagent) The ability to introduce the 2-iodobenzoic acid motif released from benziodoxolones has first been noticed by Ochiai in an isolated example of radical benzoyloxylation of THF [32], and by Gouverneur in the study of trifluoromethylation of allylsilanes [33

Atom-economical group-transfer reactions with hypervalent iodine compounds

• Andreas Boelke,
• Peter Finkbeiner and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2018, 14, 1263–1280, doi:10.3762/bjoc.14.108

• atom efficiency. Keywords: atom economy; benziodoxolones; homogeneous catalysis; hypervalent iodine; iodonium salts; Introduction Atom economy (AE) is an important parameter which helps to evaluate the overall efficiency of a chemical reaction or a chemical process [1][2]. It is defined as the

• lead to an overall AE of up to 70% but also produces synthetically versatile intermediates for subsequent transformations, in particular metal-catalyzed cross-coupling reactions. If benziodoxolones or benziodoxoles are used as group-transfer reagents, nearly 100% AE is possible since the counterion

• arylations with moderate AE to highly atom efficient transformations using alkynyl and azide-substituted benziodoxolones. The given AE values are simplified and were calculated on the basis of the key substrates, whereas the required equivalents of all starting materials (iodane and usually its reaction

m-Iodosylbenzoic acid – a convenient recyclable reagent for highly efficient aromatic iodinations

• Andreas Kirschning,
• Mekhman S. Yusubov,
• Roza Y. Yusubova,
• Ki-Whan Chi and
• Joo Y. Park

Beilstein J. Org. Chem. 2007, 3, No. 19, doi:10.1186/1860-5397-3-19

• iodine to HOI which serves as the reactive electrophilic intermediate (Scheme 2). From the results collected it can be concluded that m-iodosylbenzoic acid 6 shows a similar reactivity as 1-(arenesulfonyloxy)benziodoxolones 4a-f [36][37]. However, reagent 6 is cheaper and exerts better selectivity in the