33064-24-3Relevant articles and documents
Ultrasound assisted synthesis of 1,5-disubstituted pyrazole using Cu(I) catalyst
Pise, Ashok S.,Burungale, Arvind S.,Devkate, Santosh S.
, p. 575 - 579 (2020/02/06)
A new efficient and convenient approach towards the synthesis of pyrazole is described. The α,β-unsaturated cyanoesters were obtained from substituted benzaldehyde and ethyl cyanoacetate by reported methods. 1,5-Disubstituted pyrazoles were synthesized fr
Heterocyclic Allylsulfones as Latent Heteroaryl Nucleophiles in Palladium-Catalyzed Cross-Coupling Reactions
Markovic, Tim,Murray, Philip R.D.,Rocke, Benjamin N.,Shavnya, Andre,Blakemore, David C.,Willis, Michael C.
, p. 15916 - 15923 (2018/11/23)
Heterocyclic sulfinates are effective reagents in palladium-catalyzed coupling reactions with aryl and heteroaryl halides, often providing high yields of the targeted biaryl. However, the preparation and purification of complex heterocylic sulfinates can be problematic. In addition, sulfinate functionality is not tolerant of the majority of synthetic transformations, making these reagents unsuitable for multistep elaboration. Herein, we show that heterocyclic allylsulfones can function as latent sulfinate reagents and, when treated with a Pd(0) catalyst and an aryl halide, undergo deallylation, followed by efficient desulfinylative cross-coupling. A broad range of allyl heteroarylsulfones are conveniently prepared, using several complementary routes, and are shown to be effective coupling partners with a variety of aryl and heteroaryl halides. We demonstrate that the allylsulfone functional group can tolerate a range of standard synthetic transformations, including orthogonal C- and N-coupling reactions, allowing multistep elaboration. The allylsulfones are successfully coupled with a variety of medicinally relevant substrates, demonstrating their applicability in demanding cross-coupling transformations. In addition, pharmaceutical agents crizotinib and etoricoxib were prepared using allyl heteroaryl sulfone coupling partners, further demonstrating the utility of these new reagents.
Oxone-mediated facile access to substituted pyrazoles
Kashiwa, Mitsuhiro,Kuwata, Yoshiyuki,Sonoda, Motohiro,Tanimori, Shinji
, p. 304 - 311 (2015/12/30)
An Oxone-mediated transition-metal-free oxidative C-N bond formation has been achieved for the regioselective synthesis of substituted pyrazoles. The reactions accompany the chelation-controlled ortho-oxidation of N-substituted aromatic ring to provide ph
