- Two-Step Synthesis of 3,4-Dihydropyrrolopyrazinones from Ketones and Piperazin-2-ones
-
An expedient two-step synthesis of 3,4-dihydropyrrolopyrazinones has been achieved via a Vilsmeier-Haack reaction of ketones, followed by an annulation of the corresponding chloroaldehydes with commercially available piperazin-2-ones. A variety of cyclic and acyclic ketones and piperazin-2-ones participated in this two-step chemistry, affording the desired 3,4-dihydropyrrolopyrazinones in up to 78% yield.
- Sandoval, Cosme,Lim, Ngiap-Kie,Zhang, Haiming
-
p. 1252 - 1255
(2018/02/22)
-
- Thermolysis of N-aryl enaminoimine hydrochloride derivatives: A short and general method for the synthesis of pyranoquinolin-3-one and pyranoacridin-3-one derivatives
-
A short synthesis of 3H-pyrano[3,2-f]quinolin-3-one, 3H-acenaphtho[1,2-b]pyrano-[3,2-f]quinolin-3-one, and 3H-benzo[h]pyrano[3,2-a]acridin-3-one derivatives are described via thermolysis of suitable enaminoimine hydrochloride derivatives.
- Patra, Prasanta,Kar, Gandhi K.,Khatua, Biswajit
-
p. 1306 - 1310
(2015/04/27)
-
- A general and efficient approach to 2H-indazoles and 1H-pyrazoles through copper-catalyzed intramolecular N-N bond formation under mild conditions
-
A new efficient copper-catalyzed intramolecular amination reaction has been developed to readily synthesise a wide variety of multi-substituted 2H-indazole and 1H-pyrazole derivatives from easily accessible starting materials under mild conditions. A highly selective ligand for estrogen receptor β was prepared in three steps by employing this method. The Royal Society of Chemistry 2011.
- Hu, Jiantao,Cheng, Yongfeng,Yang, Yiqing,Rao, Yu
-
supporting information; experimental part
p. 10133 - 10135
(2011/10/09)
-
- Titanacyclobutenes or titanium vinyl carbene complexes? Reactivity of organotitanium species generated by the reaction of γ-chloroallyl sulfides with a titanocene(II) reagent
-
The reactivity of the organotitanium species generated by the reductive titanation of γ-chloroallyl sulfides with the titanocene(II) reagent [Cp2Ti{P(OEt)3}2] was studied. The organotitanium species formed from α-monosubstituted γ-chloroallyl sulfides reacted with 1,5-diphenylpentan-3-one and styrene to produce conjugated dienes and vinyl cyclopropanes as major products, thus suggesting the formation of vinyl carbene complexes as intermediates. On the contrary, the organotitanium species generated from acyclic β,γ-disubstituted γ-chloroallyl sulfides revealed titanacyclobutene-like reactivity, and their reaction with 1,5-diphenylpentan-3-one produced homoallyl alcohols. These organotitanium species did not react with styrene, but did react with dichlorophenylphosphine to afford phosphacyclobutenes. In the case of β-monosubstituted, γ-monosubstituted, and α,γ- disubstituted γ-chloroallyl sulfides, the organotitanium species reacted with both 1,5-diphenylpentan-3-one and styrene. The former reaction produced homoallyl alcohols and the latter gave vinyl cyclopropanes or unconjugated dienes. These results suggest that titanacyclobutenes and/or titanium vinyl carbene complexes are produced by the reductive titanation of γ-chloroallyl sulfides depending on their substitution patterns.
- Shono, Tomohiro,Kurashige, Rie,Mukaiyama, Ryo,Tsubouchi, Akira,Takeda, Takeshi
-
p. 4074 - 4080
(2008/02/08)
-
- Synthesis of new thieno[b]azepinediones from α-methylene ketones
-
New substituted 6,7-dihydro-4H-thieno[3,2-b]azepine-5,8-diones were synthesized in seven steps, starting from substituted α-methylene ketones, via 3-aminothiophene-2-carboxylic acid alkyl esters.
- Migianu, Evelyne,Kirsch, Gilbert
-
p. 1096 - 1100
(2007/10/03)
-
- Synthesis and carbonylation of aryl acetylenes
-
Several substituted aryl acetylenes have been prepared from acetophenones using the Vilsmeier reaction. Carbonylation of aryl acetylenes to produce aryl acrylic acids has been studied as a potential route to optically pure anti-inflammatory drugs such as ibuprofen and naproxen.
- Kotha,Tafesh,Davenport,Ortiz
-
p. 1166 - 1169
(2007/10/03)
-
- Novel pyridine-formation reactions of 2-(phosphoranylideneamino)acrylaldehydes with acetylenic esters. Synthesis of 2-mono-and 2,5-disubstituted nicotinates
-
Preparation of 2-(phosphoranylideneamino)acrylaldehydes, novel formyl-substituted (vinylimino)phosphoranes, was accomplished by the reaction of formyl-2H-azirines with triphenylphosphine. Their novel pyridine-formation reactions with acetylenic esters ach
- Kanomata, Nobuhiro,Nakata, Tadashi
-
p. 2551 - 2558
(2007/10/03)
-
- Variable Reaction Pathways for the Action of Polysulfide on Michael Acceptors
-
α,β-Unsaturated enones and cinnamaldehyde are treated with ethanolic sodium polysulfide and the product mixtures are analyzed to ascertain the types of products. 2'-Methoxychalcone reacts to give a thiolane wherein C-2 of one chalcone unit forms a carbon-
- LaLonde, Robert T.,Florence, Robert A.,Horenstein, Benjamin A.,Fritz, Richard C.,Silveira, Linda,et al.
-
-