Pd催化的吡啶三氟甲磺酸酯与N-Boc苯肼的偶联反应

Hydrazine derivatives are versatile intermediates in synthetic organic chemistry, which are widerly used for the preparation of heterocylic compounds containing N-N bond, such as pyrazoles and indazoles. Recently, transition metal catalyzed C-N coupling has become a new approach for the synthesis of N,N'-diaryl hydrazines. So far the coupling of N-Boc arylhydrazine with heteroaromatic halides (or triflates) has never been reported. In this paper, we have accomplished the synthesis of N-pyridyl-N'-phenylhydrazide 3 in 58% yield by coupling of pyridyl triflate 1 with N-Boc phenylhydrazine (2) using palladium acetate as the catalyst precursor, tri-tert-butylphosphine as the ligand, cesium carbonate as the base and toluene as the solvent.