title: Base mediated 1,3-dipolar cycloaddition of α-substituted vinyl phosphonates with diazo compounds for synthesis of 3-pyrazolylphosphonates and 5-pyrazolcarboxylates.
abstract: 5-Aryl-substituted pyrazol-3-ylphosphonates have been conveniently synthesized by 1,3-dipolar cycloaddition of 1-formamidovinylphosphonates and aryldiazomethanes under K2CO3/MeOH conditions at room temperature. These pyrazoles are formed in one pot via spontaneous elimination of formamide. Basic conditions prevent competitive formation of cyclopropylphosphonates. 3-Aryl substituted pyrazol-5-carboxylates can be synthesized by the same methodology from 1-arylvinylphosphonates and ethyl diazoacetate, although a stronger base NaH is necessary to ensure the success of the aromatization stage with the elimination of the diethoxylphosphoryl moiety.
authors.affiliation: Department of Chemistry, Moscow State University, Leninskie Gory, GSP-1, 119991 Moscow, Russian Federation. goulioukina@org.chem.msu.ru and Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Leninsky Pr. 31, 119071 Moscow, Russian Federation.
authors.forename: Nataliya S
authors.identifier: http://orcid.org/0000-0002-3823-3999
authors.initials: NS
authors.lastname: Goulioukina
authors.affiliation: Department of Chemistry, Moscow State University, Leninskie Gory, GSP-1, 119991 Moscow, Russian Federation. goulioukina@org.chem.msu.ru.
authors.forename: Nikolay N
authors.initials: NN
authors.lastname: Makukhin
authors.affiliation: Department of Chemistry, Moscow State University, Leninskie Gory, GSP-1, 119991 Moscow, Russian Federation. goulioukina@org.chem.msu.ru.
authors.forename: Egor D
authors.initials: ED
authors.lastname: Shinkarev
authors.affiliation: Department of Chemistry, Moscow State University, Leninskie Gory, GSP-1, 119991 Moscow, Russian Federation. goulioukina@org.chem.msu.ru.
authors.forename: Yuri K
authors.initials: YK
authors.lastname: Grishin
authors.affiliation: Department of Chemistry, Moscow State University, Leninskie Gory, GSP-1, 119991 Moscow, Russian Federation. goulioukina@org.chem.msu.ru.
authors.forename: Vitaly A
authors.initials: VA
authors.lastname: Roznyatovsky
authors.affiliation: Department of Chemistry, Moscow State University, Leninskie Gory, GSP-1, 119991 Moscow, Russian Federation. goulioukina@org.chem.msu.ru and Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Leninsky Pr. 31, 119071 Moscow, Russian Federation.
authors.forename: Irina P
authors.initials: IP
authors.lastname: Beletskaya