C–C bond through a radical process is described. The sequence comprises an initial in situ generation of a putative iron hydride followed by a hydrogenatomtransfer to an alkene, a coupling with a hydrazone, and a final reduction of the nitrogen-centered radical. Hydrogenation of the obtained hydrazines renders amines, including valuable tert-alkyl amines.
spirocyclic pyrazolidines in a one-pot process was developed. The gold-catalyzed three-component coupling of alkynols, hydrazines and aldehydes or ketones likely proceeds via cycloisomerization of the alkynol to an exocyclic enol ether and subsequent [3 + 2]-cycloaddition of an azomethine ylide. A library of 29 derivatives with a wide range of functional groups was synthesized in up to 97% yield. With this new
An efficient solid-phase synthesis of 3-substituted and 3,3-disubstituted 1,2-dialkylpyrazolidine-3,5-diones
作者:Rongjun He、Yulin Lam
DOI:10.1039/b802648c
日期:——
An efficient and regioselective procedure for the synthesis of di-, tri- and fully-substituted pyrazolidine-3,5-diones on a solid-phase format is described. Microwave irradiation provided significant rate enhancement in this protocol. To demonstrate the versatility of this chemistry, a representative set of 25 compounds was prepared.
I<sub>2</sub> mediated synthesis of 5-substituted-3-methyl/benzyl-1,3,4-oxadiazol-2(3H)-ones via sequential condensation/oxidative cyclization and rearrangement
A simple and efficient iodine-assisted protocol for the synthesis of 5-substituted-3-methyl/benzyl-1,3,4-oxadiazol-2(3H)-ones has been developed. The reaction involves a sequential condensation followed by tandem oxidative cyclization and rearrangement of readily available methyl/benzyl carbazates and aldehydes as starting substrates. The presence of iodine and base promotes intramolecular C–O bond
One-Pot Synthesis of Protected Benzylhydrazines from Acetals
作者:Anton Mastitski、Siret Niinepuu、Tõiv Haljasorg、Jaak Järv
DOI:10.1080/00304948.2018.1468983
日期:2018.7.4
derivatives of hydrazine are used for synthesis of various heterocyclic compounds, pharmaceutical substances, agricultural chemicals and modified peptides. In the structure of aza-peptides at least one amino acid residue is substituted by a hydrazino acid and this modification greatly improves the proteolytic stability of a peptide, which, in turn, makes aza-peptides promising drug candidates. Due to the