90642-57-2Relevant articles and documents
Sequential Addition/Elimination/Annulation Reactions of 4-Pentynones with Benzylamine and Ammonia
Arcadi, Antonio,Rossi, Elisabetta
, p. 667 - 668 (1997)
The sequential addition/elimination/cycloammination of 4-pentynones in the presence of benzylamine or ammonia produces 1,2,3,-5-substituted and 2,3,5-substituted pyrroles and fused pyrrole sytems, respectively in good to high yields. The methodology has been extended to the preparation of the 17β-hydroxyandrost-4-ene[3,2-b](1-benzyl-5-methyl)pyrrole.
Regioselective synthesis of 2,3,4- or 2,3,5-trisubstituted pyrroles via [3,3] or [1,3] rearrangements of O-vinyl oximes
Wang, Heng-Yen,Mueller, Daniel S.,Sachwani, Rachna M.,Kapadia, Rachel,Londino, Hannah N.,Anderson, Laura L.
supporting information; experimental part, p. 3203 - 3221 (2011/06/24)
The regioselective synthesis of 2,3,4- or 2,3,5-trisubstituted pyrroles has been achieved via [3,3] and [1,3] sigmatropic rearrangements of O-vinyl oximes, respectively. Iridium-catalyzed isomerization of easily prepared O-allyl oximes enables rapid access to O-vinyl oximes. The regioselectivity of pyrrole formation can be controlled by either the identity of the α-substituent or through the addition of an amine base. When enolization is favored, a [3,3] rearrangement followed by a Paal-Knorr cyclization provides a 2,3,4-trisubstituted pyrrole; when enolization is disfavored, a [1,3] rearrangement occurs prior to enolization to produce a 2,3,5-trisubstituted pyrrole after cyclization. Optimization and scope of the O-allyl oxime isomerization and subsequent pyrrole formation are discussed and mechanistic pathways are proposed. Conditions are provided for selecting either the [3,3] rearrangement or the [1,3] rearrangement product with β-ester O-allyl oxime substrates.
Palladium-catalyzed amino-heck reaction of γ,δ-unsaturated ketone O-diethylphosphinyloximes: A new synthesis of substituted pyrroles and indoles
Zhu, Jia-Liang,Chan, Yu-Hui
scheme or table, p. 1250 - 1254 (2009/04/06)
γ,δ-Unsaturated ketone O-diethylphosphinyloximes, readily prepared from the corresponding ketones, were used as starting materials for the intramolecular amino-Heck reactions. In the presence of a catalytic amount of Pd(PPh3)4 in DBU, cyclization reactions occurred preferentially via a 5-exo fashion to afford a variety of 2-substituted 5-methyl-1H-pyrroles and several indole derivatives in moderate to high yields. Georg Thieme Verlag Stuttgart.
Synthesis of pyrroles via copper-catalyzed coupling of amines with bromoenones
Pan, Yuanjia,Lu, Hongjian,Fang, Yewen,Fang, Xinqiang,Chen, Liqun,Qian, Junlu,Wang, Junhua,Li, Chaozhong
, p. 1242 - 1246 (2008/02/02)
The CuI/N,N-dimethylglycine hydrochloride catalyzed reactions of amines with γ-bromo-substituted γ,δ-unsaturated ketones in the presence of K3PO4 and NH4OAc led to the formation of the corresponding polysubstituted pyrrole
Nitrogen fixation: Synthesis of heterocycles using molecular nitrogen as a nitrogen source
Mori, Miwako,Akashi, Masaya,Hori, Masanori,Hori, Katsutoshi,Nishida, Mayumi,Sato, Yoshihiro
, p. 1655 - 1670 (2007/10/03)
Nitrogen fixation using transition metals is a fascinating process. We have already reported on the incorporation of molecular nitrogen into organic compounds using a titanium-nitrogen complex reported by Yamamoto. We developed a novel titanium-catalyzed nitrogenation procedure using TiCl4 in the presence of an excess amount of Li and TMSCl. In this reaction, a 1 atm pressure of nitrogen gas can be used and the reaction proceeds at room temperature. The procedure is very simple. A THF solution of TiCl4 or Ti(O iPr)4 (1 equiv.), Li (10 equiv.), and TMSCl (10 equiv.) was stirred under an atmosphere of nitrogen at room temperature overnight to give titanium-nitrogen complexes. Although the structures of the titanium-nitrogen complexes have not yet been determined, they would consist of N(TMS)3, X2TiN(TMS)2, and XTi=NTMS. Using this procedure, various heterocycles, such as indole, quinoline, pyrrole, pyrrolizine, and indolizine derivatives, could be synthesized from molecular nitrogen in good-to-moderate yields as a stoichiometric reaction based on a titanium complex by a one-pot reaction. Furthermore, monomorine I and pumiliotoxin C were synthesized from molecular nitrogen as a nitrogen source. This procedure was further extended for the syntheses of heterocycles using a catalytic amount of titanium complex; also, indole and pyrrole derivatives were obtained in high yields.
The first chemoselective synthesis of functionalized 3-vinylpyrroles
Trofimov, Boris A.,Demenev, Andrey P.,Sobenina, Lyubov' N.,Mikhaleva, Al'bina I.,Tarasova, Ol'ga A.
, p. 3501 - 3503 (2007/10/03)
3-(1-Alkylthio-2-cyano-2-X-ethenyl)pyrroles (X=CN, CONH2, CO2Et) have been synthesized in 28-58% yields by the reaction of pyrrole-3-carbodithioates with CH-acids (malononitrile, cyanoacetamide, cyanoacetate) in the KOH-DMSO system.
Synthesis of functionalised furans and pyrroles through annulation reactions of 4-pentynones
Arcadi, Antonio,Rossi, Elisabetta
, p. 15253 - 15272 (2007/10/03)
A new approach to 4-pentynones through palladium-catalysed coupling reaction of the ready available 2-propynyl ketones with aryl iodides and/or vinyl triflates is proposed. Annulation reactions of both 2-propynyl ketones and 4-pentynones gave functionalised furans using potassium tert-butoxide in DMF and functionalised pyrroles in the presence of benzylamine or ammonia, respectively in good to high yields. The methodology has been extended to the preparation of 17β-hydroxyandrost-4-en[3,2-b](5-methyl)furan and to 17β- hydroxyandrost-4-en[3,2-b](1-benzyl-5-methyl)pyrrole. A different reaction pattern was observed when the 4-pentynones were treated with sodium methoxide in MeOH. The influence of the reaction medium on the outcome of the annulation reaction in the case of one 2-pentyn-1,6-dione (heteroannulation vs. carbocyclization) is also shown.
A NEW SYNTHETHIC ASPECT OF ACETIC NITRONIC ANHYDRIDES
Miyashita, Masaaki,Awen, Bahlul Z. E.,Yoshikoshi, Akira
, p. 7569 - 7586 (2007/10/02)
A facile and convenient synthesis of acetic nitronic anhydrides from aliphatic nitroalkenes and lithium ketone enolates and the efficient conversion of these anhydrides to 1,4-diketones, alkylpyrroles, diketone monooximes, dihydro-1,2-oxazines, pyrrolidin
Convenient and General Synthesis of Polyalkylpyrroles from Ketones and Nitroalkenes
Miyashita, Masaaki,Awen, Bahlul Z. Elstaiwi,Yoshikoshi, Akira
, p. 841 - 842 (2007/10/02)
A convenient and general methos has been developed for the synthesis of polyalkylpyrroles starting from ketones and nitroalkenes via reduction of the intermediate acetic nitronic anhydrides.
