3 research outputs found
Divergent Construction of Pyrazoles via Michael Addition of N‑Arylhydrazones to 1,2-Diaza-1,3-dienes
partially_open4noThe base (NaH)-promoted Michael addition of
N-arylhydrazones (AHs) with 1,2-diaza-1,3-dienes (DDs)
produces unprecedented β-azohydrazone adducts. Strategically,
the use of AHs as acyl anion equivalents (d1 synthon)
and DDs as α-electrophiles (a2 synthon) of carbonyl
compounds open the way to two important classes of pyrazole
compounds.embargoed_20160409Serena mantenuto; Fabio Mantellini; Orazio Attanasi; Gianfranco FaviMantenuto, Serena; Mantellini, Fabio; Attanasi, ORAZIO ANTONIO; Favi, Gianfranc
Divergent Construction of Pyrazoles via Michael Addition of <i>N</i>‑Arylhydrazones to 1,2-Diaza-1,3-dienes
The base (NaH)-promoted Michael addition
of <i>N</i>-arylhydrazones
(AHs) with 1,2-diaza-1,3-dienes (DDs) produces unprecedented β-azohydrazone
adducts. Strategically, the use of AHs as acyl anion equivalents (<i>d</i><sup>1</sup> synthon) and DDs as α-electrophiles
(<i>a</i><sup>2</sup> synthon) of carbonyl compounds open
the way to two important classes of pyrazole compounds
Interceptive [4 + 1] Annulation of in Situ Generated 1,2-Diaza-1,3-dienes with Diazo Esters: Direct Access to Substituted Mono‑, Bi‑, and Tricyclic 4,5-Dihydropyrazoles
In situ derived acyclic and cyclic
1,2-diaza-1,3-dienes (DDs) were
engaged in interceptive [4 + 1] annulation strategy with diazo esters
(DEs). The catalytic activity of inexpensive copperÂ(II) chloride allows
the direct synthesis of mono-, bi-, and tricyclic 4,5-dihydropyrazole-5-carboxylic
acid derivatives in a process that circumvents the use of an anhydrous
and inert atmosphere