A base-controlled divergent cyclization between 2-mercaptobenzimidazoles and β-CF₃-1,3-enynes providing either trifluoromethylated or fluorinated benzo[4,5]imidazo[2,1-b][1,3]thiazines has been developed. The β-CF₃-1,3-enyne, as a three-carbon synthon, underwent a 1,8-diazabicyclo[5.4.0] undec-7-ene (DBU)-catalyzed tandem hydroamination/intramolecular hydrothiolation to give CF₃-substituted 3,4-dihydro-2H-benzo[4,5]imidazo[2,1-b][1,3]thiazine, whereas reaction with KOH afforded fluorinated 4H-benzo[4,5]imidazo[2,1-b][1,3]thiazine exclusively. In addition, the synthetic utility of this methodology was showcased through a variety of downstream derivatizations.

中文翻译：

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由2-巯基苯并咪唑和β-CF3-1,3-烯炔碱控制发散合成含氟苯并[4,5]咪唑并[2,1-b][1,3]噻嗪

已经开发出2-巯基苯并咪唑和β-CF ₃ -1,3-烯炔之间的碱基控制发散环化，提供三氟甲基化或氟化苯并[4,5]咪唑并[2,1- b ][1,3]噻嗪。β-CF ₃ -1,3-烯炔作为三碳合成子，经过1,8-二氮杂双环[5.4.0]十一碳7-烯(DBU)催化的串联氢胺化/分子内氢硫醇化得到CF ₃ -取代的3,4-二氢-2 H -苯并[4,5]咪唑并[2,1- b ][1,3]噻嗪，而与KOH反应得到氟化的4 H -苯并[4,5]咪唑[2 ,1- b ][1,3]噻嗪。此外，通过各种下游衍生化展示了该方法的合成效用。