Synthesis of Densely Functionalized 3a,4-Dihydro-1H-Pyrrolo[1,2-b]Pyrazoles via Base Mediated Domino Reaction of Vinyl Malononitriles with 1,2-Diaza-1,3-dienes
摘要:
A domino reaction of vinyl malononitriles (VMs) with 1,2-diaza-1,3-dienes (DDs) produce unprecedented 3a,4-dihydro-1H-pyrrolo[1,2-b]pyrazole systems in a chemo-, regio-, and stereoselective fashion. This base promoted (DIPEA) one-pot transformation involving multiple steps constructs one new C-C bond, two C-N bonds, and two new fused heterocyclic rings with total atom economy.
A tandem reaction of heterocyclic ketene aminals and 1,2-diaza-1,3-dienes was developed for the expedient synthesis of pyrimidopyrrolopyridazine derivatives. This process involved an intramolecular conjugate addition followed by CuCl2-catalyzed hydrazone formation.
Zn(II)-Catalyzed Addition of Aromatic/Heteroaromatic C(sp<sup>2</sup>)–H to Azoalkenes: A Polarity-Reversed Arylation of Carbonyl Compounds
作者:Cecilia Ciccolini、Lucia De Crescentini、Fabio Mantellini、Stefania Santeusanio、Gianfranco Favi
DOI:10.1021/acs.orglett.9b01628
日期:2019.6.7
An umpolung α-(hetero)arylation strategy that involves the Michael-type reaction between electron-rich (hetero)aromatic substrates and azoalkenes is developed. The reaction proceeds under very mild conditions at room temperature and in the presence of inexpensive, nontoxic ZnCl2 catalyst to provide access to otherwise inaccessible hydrazone structures. Subsequent hydrolysis of these latter to ketones
Regioselective synthesis of spiro-cyclopropanated 1-aminopyrrol-2-ones by Bi(OTf)3-catalyzed one-pot ‘Mukaiyama–Michael addition/cyclization/ring-contraction’ reactions of 1,2-bis(trimethylsilyloxy)cyclobutene with 1,2-diaza-1,3-butadienes
作者:Orazio A. Attanasi、Gianfranco Favi、Gianluca Giorgi、Fabio Mantellini、Vahuni Karapetyan、Peter Langer
DOI:10.1016/j.tet.2009.04.018
日期:2009.7
Unknown spiro-cyclopropanated 1-aminopyrrol-2-ones are regioselectively prepared in high yields by Bi(OTf)3-catalyzed one-pot ‘Mukaiyama–Michael addition/cyclization/ring-contraction’ reactions of 1,2-bis(trimethylsilyloxy)cyclobutene with 1,2-diaza-1,3-butadienes at room temperature.
Substrate-controlled reactions have been developed for the synthesis of spirocyclopropylpyrazolones and bicyclic 4,5-dihydropyrazoles from 1,2-diaza-1,3-dienes and sulfur ylides. These protocols were carried out under mild reaction conditions without any additives in generally moderate to good yields. Plausible mechanisms for the transformations were proposed.
Synthesis of Densely Functionalized 3a,4-Dihydro-1<i>H</i>-Pyrrolo[1,2-<i>b</i>]Pyrazoles via Base Mediated Domino Reaction of Vinyl Malononitriles with 1,2-Diaza-1,3-dienes
作者:Orazio A. Attanasi、Gianfranco Favi、Athina Geronikaki、Fabio Mantellini、Giada Moscatelli、Aliki Paparisva
DOI:10.1021/ol401336s
日期:2013.6.7
A domino reaction of vinyl malononitriles (VMs) with 1,2-diaza-1,3-dienes (DDs) produce unprecedented 3a,4-dihydro-1H-pyrrolo[1,2-b]pyrazole systems in a chemo-, regio-, and stereoselective fashion. This base promoted (DIPEA) one-pot transformation involving multiple steps constructs one new C-C bond, two C-N bonds, and two new fused heterocyclic rings with total atom economy.