Guru Murali Mohan, De Sriman, Dutta Sayan, Koley Debasis, Maji Biplab
Department of Chemical Sciences , Indian Institute of Science Education and Research Kolkata , Mohanpur-741246 , India . Email:
Chem Sci. 2019 Jul 5;10(34):7964-7974. doi: 10.1039/c9sc02492a. eCollection 2019 Sep 14.
Tris(pentafluorophenyl)borane-catalyzed dehydrogenative-cyclization of -tosylhydrazones with aromatic amines has been disclosed. This metal-free catalytic protocol is compatible with a range of functional groups to provide both symmetrical and unsymmetrical 3,4,5-triaryl-1,2,4-triazoles. Mechanistic experiments and density functional theory (DFT) studies suggest an initial Lewis adduct formation of -tosylhydrazone with B(CF) followed by sequential intermolecular amination of the borane adduct with aniline, intramolecular cyclization and frustrated Lewis pair (FLP)-catalyzed dehydrogenation for the generation of substituted 1,2,4-triazoles.
已公开三（五氟苯基）硼烷催化对甲苯磺酰腙与芳香胺的脱氢环化反应。这种无金属催化方案与一系列官能团兼容，可提供对称和不对称的3,4,5-三芳基-1,2,4-三唑。机理实验和密度泛函理论（DFT）研究表明，对甲苯磺酰腙与B(CF)首先形成路易斯加合物，随后硼烷加合物与苯胺进行连续的分子间胺化、分子内环化以及受阻路易斯对（FLP）催化的脱氢反应，以生成取代的1,2,4-三唑。
