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Diazonium salts, and precisely arenediazonium o-benzenedisulfonimides, have been used for the first time as efficient electrophilic partners in gold catalyzed Heck-coupling reactions. The synthetic protocol was general, easy and gave the target products in satisfactory yields. Mechanistic insights revealed the fundamental roles of the o-benzenedisulfonimide anion as an electron transfer agent thath promotes a radical pathway that does not require the presence of photocatalysts or external oxidants.

Arene and heteroarenediazonium o-benzenedisulfonimides can be used as efficient reagents in Sandmeyer cyanation. This work reports such reactions carried out by us under very mild conditions using tetrabutyl ammonium cyanide as a safe cyanide source and, interestingly, without the need for a Cu catalyst. The reactions have given rise to aryl nitriles in good yields (25 examples, average yield 75%). A good amount of o-benzenedisulfonimide was recovered from each reaction and then reused to prepare other salts. Mechanistic insights have allowed us to highlight the fundamental role of the o-benzenedisulfonimide anion as an electron transfer agent.

Two chiral derivatives of 1,2-benzenedisulfonimide, namely 4-methyl-3,6-bis(o-tolyl)-1,2-benzenedisulfonimide and 4,5-dimethyl-3,6-bis(o-tolyl)-1,2-benzenedisulfonimide, have been easily synthesized in good overall yields (respectively 34% and 41%) by means of an eleven-step synthetic protocol from commercially available 2-methyl-6-nitroaniline or 2,3-dimethyl-6-nitroaniline. 4,5-Dimethyl-3,6-bis(1-naphthyl)-1,2-benzenedisulfonimide was also synthesized, but the overall yield from 2,3-dimethyl-6-nitroaniline was lower (9%). The atropisomers of these compounds have been resolved and (-)atropisomers have been demonstrated to be efficient chiral catalysts in the Strecker reaction.

o-Benzenedisulfonimide (OBS) has efficiently catalysed the one-pot three-component reaction of ketones and aromatic amines with trimethylsilyl cyanide (TMSCN) giving the corresponding α-amino nitriles in excellent yields (23 examples; average yield 85%). Reaction conditions were very simple, green and efficient. Theoretical calculations have allowed us to explain the mechanism of this reaction which has been found to take place in two phases; the first consists of the nucleophilic addition of the aniline to the ketone and the subsequent dehydration to an imine; the second one consists of the formal addition of cyanide anion to the protonated imine. OBS acts in all steps of this mechanism. Without an acid catalyst, the reaction mechanism is more simple but barriers are sensibly higher. A chiral derivative of OBS was also used and gave fairly good results.

An efficient and practical synthesis of triaryl and trisindolylmethanes is reported via the bisarylation of aryl aldehydes with activated arenes. The new method features mild solvent-free reaction conditions, in most cases nearly stoichiometric reagent ratios, catalytic amount of the readily available, easily-handled, recoverable and reusable Brønsted acid catalyst o-benzenedisulfonimide.

o-Benzenedisulfonimide, a new strong bench-stable Brønsted acid, has been shown to efficiently catalyze the Mukaiyama aldol reaction of aldehydes or dimethyl acetals with silyl enol ethers under mild solvent-free reaction conditions.