Visible-light photocatalyzed synthesis of 2-aryl N-methylpyrroles, furans and thiophenes utilizing arylsulfonyl chlorides as a coupling partner

Visible-light (Blue LED lamp: hν=425±15 nm) photocatalyzed cross-coupling reactions of arylsulfonyl chloride with N-methylpyrrole, furan, thiophene and their derivatives have been achieved in moderate to good yields at room temperature. A plausible mechanism has been proposed for the reaction. The arylation takes place at the C-H bond (C2-H or C5-H) next to the heteroatom with a high regioselective manner! Moreover, arylsulfonyl chlorides utilized in this study are inexpensive, environmentally benign and relatively more stable towards temperature, moisture and air as compared to diazonium salts normally used as coupling partners in the previously reported methods for the synthesis of heterobiaryls through visible-light photocatalyzed conditions.

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