A chiral derivative of 1,2-benzenedisulfonimide, namely (-)-4,5-dimethyl-3,6-bis(o-tolyl)-1,2-benzenedisulfonimide is herein proven to be an efficient chiral catalyst in a one pot three-component Biginelli reaction. In fact the yields of the target dihydropyrimidines were very high (25 examples; average 91%) and enantiomeric excesses were always excellent (14 examples; average 97%). Ultimately, we herein propose a sustainable procedure that ensures that the principles of Green Chemistry are met. The reaction displays a number of green benefits and advantages including the total absence of solvents, mild reaction conditions, relatively short reaction times and the stoichiometric reagent ratio. Target dihydropyrimidines are obtained in adequate purity, making further cromatographic purification unnecessary. Moreover, the chiral catalyst was easily recovered from the reaction mixture and reused, without the loss of catalytic activity.
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.
Reactions between various benzyl alcohols or tert-butyl alcohol and nitriles were carried out in the presence of catalytic amounts (usually 10-20 mol-%) of o-benzenedisulfonimide as a Brønsted acid catalyst; the reaction conditions were mild and the yields of amides were good. The catalyst
Acid-catalyzed organic reactions, such as etherification, esterification, acetal synthesis, cleavage, and interconversion, and pinacol rearrangement were carried out in the presence of catalytic amounts of o-benzenedisulfonimide as Brønsted acid catalyst; the conditions were mild and selective. The catalyst was easily recovered and purified, ready to be used in further reactions, with economic and ecological advantages.
The reaction between various arenediazonium o-benzenedisulfonimides and triorganoindium compounds is described. Depending on the reaction conditions, it is possible to obtain biaryls (16 examples, average yield of 79 %) or diaryldiazenes (18 examples, average yield of 81 %). o-Benzenedi-
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