This synthetic approach led to the formation of γ-sultone α-carbonitrile 191 with yields ranging from 30% to 56% (Figure ). The yields were comparatively lower in contrast to similar experiments with sulfonyl chloride 94, primarily due to the relatively lower stability of sulfonyl chloride 188 bearing nitrile moiety under reaction and storage conditions. The scope and limitations of one-pot sulfonylationcyclization reactions is limited to highly active methylene unit. This was demonstrated by reactions with phenylmethane sulfonyl chloride 192 with cyanohydrins under the common conditions, which resulted in the formation of corresponding cyanosulfonates 193 (Scheme 35), while the subsequent cyclization required the use of stronger base t-BuOK in DMF to initiate the CSIC reaction. Therefore, α-phenyl-β-enamino-γ-sultones 195 could be obtained only using the two-step approach in good yields up to 77%. 109 In turn, the introduction of an electron-withdrawing group into the aromatic substituent of phenylmethane sulfonyl chloride could facilitate the cyclization of Osulfonylated cyanohydrins and enable a one-pot CSIC reaction. The use of (4-carbomethoxyphenyl)methane sulfonyl chloride 196 as a sulfonylating agent in the reaction with cyanohydrins 184 provided the corresponding enaminosultones 197 in moderate yields according to the common method (Scheme 36, Table ).