A metal‐free cyclization of benzo[c][1,2]dithiol‐3‐ones and amidines is demonstrated herein. Triphenylphosphine was harnessed as the activating reagent to facilitate the ring‐opening of benzo[c][1,2]dithiol‐3‐ones via S‐S bond cleavage. This PPh3‐Promoted cyclization reaction of benzo[c][1,2]dithiol‐3‐ones enabled to forge a diverse array of 1,3‐benzothiazones in good yields with wide substrate scope under mild conditions.

中文翻译：

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通过 PPh3 促进苯并[c][1,2]二硫醇-3-酮和脒的环化合成苯并[e][1,3]噻嗪-4-酮

本文证明了苯并[c][1,2]二硫醇-3-酮和脒的无金属环化。利用三苯基膦作为活化剂，通过 S-S 键断裂促进苯并[c][1,2]二硫醇-3-酮的开环。这种 PPh3 促进的苯并[c][1,2]二硫醇-3-酮环化反应能够在温和条件下以良好的收率和广泛的底物范围形成多种 1,3-苯并噻腙。