N-Ylidenbenzolsulfonamide Aus Thioxoheterocyclen Und Phenylsulfonylaziden

Direct C–H Sulfonylimination of Pyridinium Salts

“…Over the past few decades, much effort has been made to develop efficient methodologies for the synthesis of sulfonyl iminopyridine derivatives (Scheme ). − They were reportedly synthesized from sulfapyridine via the alkylation reaction; however, their formation was inevitably accompanied by the tautomer sulfonyl aminopyridine, and the mixture was mainly used for studies of their photophysical properties (Scheme a) . Another method used 2-pyridinethione as the starting material and removed the S to obtain the sulfonyl iminopyridine in a multistep reaction (Scheme b) .…”

“… − They were reportedly synthesized from sulfapyridine via the alkylation reaction; however, their formation was inevitably accompanied by the tautomer sulfonyl aminopyridine, and the mixture was mainly used for studies of their photophysical properties (Scheme a) . Another method used 2-pyridinethione as the starting material and removed the S to obtain the sulfonyl iminopyridine in a multistep reaction (Scheme b) . In 2013, Zhang and Dong reported an elegant copper-catalyzed multicomponent reaction for the efficient preparation of multifunctionalized sulfonyl iminopyridine, where the reaction selectivity could be readily tuned by changing the reaction conditions (Scheme c) .…”