Gram-scale nucleophilic aromatic substitution of 4,7-dibromo-5,6-difluoro-[2,1,3]-benzothiadiazole for Synthesis of 4,7-dibromo-5,6-BINOL-O-benzo[2,1,3]thiadiazole, and 4,7-dibromo-5,6-dicarbazol-N-ylbenzo[2,1,3]thiadiazole. The Stille coupling reaction a

https://doi.org/10.62239/jca.2025.065

Abstract

In this study, we delveloped a simple and efficient synthetic procedure for the nucleophilic substitution of 4,7-dibromo-5,6-diflourobenzo[2,1,3]thiadiazole with diols, diamines and carbazole to obtain 4,7-dibromo-5,6-dinucleophile-benzo[2,1,3]diadiazole derivatives. The chiral version of BINOL and BINAM, based on (R-/S-) atropisomers of binaphthyl, were employed as nucleophilic reagents under bases (DBU 1,8-diazabicyclo[5.4.0]undec-7-ene  and/or K2CO3). The nucleophillic carbazol-N-yl sodium species were synthesized via recrystallized and subsequent treatment in dried DMF and in the presence of strong base as NaH. All three nucleophiles participated successfully in the SnAr reaction, affording excellent yields with BINAM and quantitative yields with carbazole and BINOL.