Organic solvent-free synthesis of sulfonyl hydrazides in water

Continuous flow reactions in the preparation of active pharmaceutical ingredients and fine chemicals

“…Given our longstanding interest in terpene chemistry, our group is also engaged in the synthesis of fine chemicals by transforming commercially available terpenes. In 2015, the ring expansion of (R)-(À)-carvone ( 8) to (R)-(+)-3-methyl-6isopropenylcyclohept-3-enone-1 (10) was reported in collaboration with Steven Ley's laboratory (Scheme 3). 28 This protocol involved as the key step the continuous epoxidation of (R)-(À)-carvone (8), affording product 9 in 95% yield on a multigram scale (9.35 g, 57 mmol).…”

“…8 For example, important contributions concerning the continuous synthesis of APIs using reactive organometallic intermediates have been described. 9,10 A remarkable aspect of continuous flow technologies lies in the precise control that they offer over the essential parameters of reactions. 11 This implies advantages in terms of factors such as temperature, pressure and time, thereby promoting enhanced reactivity, increased selectivity, and consequent improvement in yields.…”

Hydrazinosulfonylation of aryl electrophiles: a straightforward approach for the synthesis of aryl N-aminosulfonamides

“…The traditional method for synthesizing N -aminosulfonamides is through the direct sulfonylation of hydrazines using sulfonyl chlorides. 9 However, the irritating nature and moisture sensitivity of sulfonyl chlorides, as well as the production of a stoichiometric halogen waste stream, are considered serious drawbacks of this procedure. An alternative protocol involves the reaction of azodicarboxylate derivatives with various sulfonylating agents such as sulfonyl chlorides, sulfinates, sulfinic acid, and thiols.…”