32770-66-4Relevant articles and documents
Sulphur promoted C(sp3)-C(sp2) cross dehydrogenative cyclisation of acetophenone hydrazones with aldehydes: Efficient synthesis of 3,4,5-trisubstituted 1H-pyrazoles
Vanjari, Rajeshwer,Guntreddi, Tirumaleswararao,Kumar, Saurabh,Singh, Krishna Nand
, p. 366 - 369 (2015)
A novel strategy for the cross dehydrogenative coupling (CDC) of acetophenone hydrazones and aldehydes has been developed for the synthesis of highly substituted pyrazoles. This work, for the first time, uses elemental sulfur as a promoter as well as a hydrogen acceptor in effecting the Csp3-Csp2 bond formation via C-H activation. This journal is
Umpolung of Carbonyl Groups as Alkyl Organometallic Reagent Surrogates for Palladium-Catalyzed Allylic Alkylation
Zhu, Dianhu,Lv, Leiyang,Li, Chen-Chen,Ung, Sosthene,Gao, Jian,Li, Chao-Jun
supporting information, p. 16520 - 16524 (2018/11/23)
Palladium-catalyzed allylic alkylation of nonstabilized carbon nucleophiles is difficult and remains a major challenge. Reported here is a highly chemo- and regioselective direct palladium-catalyzed C-allylation of hydrazones, generated from carbonyls, as a source of umpolung unstabilized alkyl carbanions and surrogates of alkyl organometallic reagents. Contrary to classical allylation techniques, this umpolung reaction utilizes hydrazones prepared not only from aryl aldehydes but also from alkyl aldehydes and ketones as renewable feedstocks. This strategy complements the palladium-catalyzed coupling of unstabilized nucleophiles with allylic electrophiles by providing an efficient and selective catalytic alternative to the traditional use of highly reactive alkyl organometallic reagents.
CYCLOADDITIONS OF DISUBSTITUTED DIAZO COMPOUNDS TO P-CHLORO(BISTRIMETHYLSILYL) METHYLENE PHOSPHINE.
Thoraval, J. Y.,Nagai, W.,Yeung Lam Ko, Y. Y. C.,Carrie, R.
, p. 3859 - 3868 (2007/10/02)
Disubstituted diazo compounds rapidly add to P-chloro (bistrimethylsilyl) methylene phosphine at low temperature. 1H, 31P and 13C NMR allow the characterization of the resulting cycloadducts and the establisment of the stereochemistry of the resulting cycloadducts which are potential precursors of ?3λ5 bis methylene phosphorane by nitrogen extrusion.