Catalytic properties and acidity of 1,2-benzenedisulfonimide and some of its derivatives. An experimental and computational study

Copper‐ and Phosphane‐Free Sonogashira Coupling of Arenediazonium o‐Benzenedisulfonimides

“…However, the anion of 2 is a weaker base than acetate. The p K a of AcOH in DMSO is 12.6,12 while the p K a of 1 is –4.2 (determined using the same method we described to calculate its p K a in butanone13), so it is unthinkable that this anion can deprotonate the very weakly acidic 3 . We suppose that the formation of a hydrogen bond between 3 and the highly basic solvent DMSO weakens the alkynyl C–H bond, and makes the carbon nucleophilic enough to form a new C–Pd bond.…”

Silica Gel-Immobilized 1,2-Benzenedisulfonimide: A New and Versatile Brønsted Acid Heterogeneous Catalyst

“…It was therefore necessary to synthesize a derivative of 1 (or one of its precursors) that bears a iodine (or bromine) atom on the aromatic ring. As shown in Scheme , according to what we have previously reported, 1,2‐benzenedisulfonimide derivative 9 was obtained from the corresponding anthranilic acid 3 …”

“…Since the double bond may be an undesired reactive site, it was thought wise to reduce it to a single bond with CuCl and NaBH 4 . The reduced adduct 6 (obtained in almost quantitative yield) was easily transformed to the corresponding sulfonyl chloride 7 (100 % yield) and finally, to the desired ethyl 3‐(1,2‐benzenedisulfonimide‐4‐yl)propionate ( 8 ; 100% yield) . It must be stressed that the sulfonimide 8 spontaneously (due to the high acidity of sulfonimide NH) tended to hydrolyse to 3‐[(1,2‐benzenedisulfonimide‐4‐yl)]propionic acid ( 9 ; 100 % yield); the overall yield (from 3 ) of this protocol was 75 %.…”

Chiral derivatives of 1,2-benzenedisulfonimide as efficient Brønsted acid catalysts in the Strecker reaction

“…Scheme 3 Synthetic protocol for isatine 11b. which, measured, was 6.09 in butanone 13 ) and polar compounds, so their chromatographic separation can be considered extremely difficult. We preferred trying to separate the atropisomers of disulfonyl chlorides 14 that have the same chiral structure as 3.…”

“…Chiral analyses were performed on a Perkin-Elmer Autosystem GC connected to a J&W Scientific Cyclosil-B column; stationary phase: 30% heptakis (2,3-di-O-methyl-6-O-t-butyldimethylsilyl)-β-cyclodextrin in DB-1701. 1 H NMR and 13 C NMR spectra were recorded on a Bruker Avance 200 spectrometer at 200 and 50 MHz respectively. IR spectra were recorded on an IR Perkin-Elmer UATR-two spectrometer.…”