Metal-free regioselective construction of 2-aryl-2H-tetrazol-5-yl difluoromethylene phosphonates

Three bench-stable difluoromethylene phosphonate hydrazones were prepared from simple diethyl(difluoromethyl)phosphonate within two steps in good yields. The [3 + 2] cycloaddition reaction of these diazo precursors with aryl diazonium salts has been accomplished under metal-free conditions with exclusive regioselectivity. This transformation provides practical access to a broad panel of 2-aryl-2H-tetrazol-5-yl difluoromethylene phosphonates, including the corresponding derivatives of amino acid (phenylalanine) and drug cores (Pomalidomide and Lapatinib fragment). (C) 2021 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.

Automated summary

Three bench-stable difluoromethylene phosphonate hydrazones were synthesized in good yields from simple diethyl(difluoromethyl)phosphonate within two steps. The [3 + 2] cycloaddition reaction with aryl diazonium salts under metal-free conditions exhibited exclusive regioselectivity. This method provides practical access to a wide range of 2-aryl-2H-tetrazol-5-yl difluoromethylene phosphonates, including derivatives of amino acids and drug cores.