A novel 1,8-diazabicyclo[5.4.0]undec-7-ene(DBU)-mediated formal cycloaddition of β,γ-alkenyl esters with p-tolylsulfonylazide(p-TsN_3) for the synthesis of 3,5-disubstituted pyrazoles has been developed.The reaction...A novel 1,8-diazabicyclo[5.4.0]undec-7-ene(DBU)-mediated formal cycloaddition of β,γ-alkenyl esters with p-tolylsulfonylazide(p-TsN_3) for the synthesis of 3,5-disubstituted pyrazoles has been developed.The reaction proceeded through diazotization of β,γ-alkenyl esters sequential with thermodynamic cyclization.p-Tolylsulfonylazide played a role as a source of two-nitrogen synthons.The reaction employs readily available starting materials,tolerates a wide range of functional groups,and proceeds under mild conditions.展开更多
基金supported by the National Natural Science Foundation of China(21622203,21472147,and 21272183)Fund of Northwest University(334100035)
文摘A novel 1,8-diazabicyclo[5.4.0]undec-7-ene(DBU)-mediated formal cycloaddition of β,γ-alkenyl esters with p-tolylsulfonylazide(p-TsN_3) for the synthesis of 3,5-disubstituted pyrazoles has been developed.The reaction proceeded through diazotization of β,γ-alkenyl esters sequential with thermodynamic cyclization.p-Tolylsulfonylazide played a role as a source of two-nitrogen synthons.The reaction employs readily available starting materials,tolerates a wide range of functional groups,and proceeds under mild conditions.
