نتایج جستجو برای: multisubstituted pyrroles

تعداد نتایج: 2001  

Journal: :Chemical communications 2014
Kazunari Nakajima Mai Kitagawa Yuya Ashida Yoshihiro Miyake Yoshiaki Nishibayashi

We have succeeded in the visible light-mediated synthetic use of α-aminoalkyl radicals derived from α-silyl secondary amines toward addition to α,β-unsaturated carbonyl compounds. The resulting γ-aminocarbonyl compounds are converted into γ-lactams and pyrroles in a one-pot process.

Journal: :Organic & biomolecular chemistry 2012
Philippa B Cranwell Matthew O'Brien Duncan L Browne Peter Koos Anastasios Polyzos Miguel Peña-López Steven V Ley

Using a simple and accessible Teflon AF-2400 based tube-in-tube reactor, a series of pyrroles were synthesised in flow using the Paal-Knorr reaction of 1,4-diketones with gaseous ammonia. An inline flow titration technique allowed measurement of the ammonia concentration and its relationship to residence time and temperature.

Journal: :Organic letters 2012
Ruslan Guliyev Seyma Ozturk Ertan Sahin Engin U Akkaya

Oxalyl-tethered pyrroles can be doubly bridged with two difluoroboron chelating units to yield bright orange dyes. Interestingly, in polar organic solvents, the addition of fluoride and cyanide result in reversible detachment of the otherwise stable difluoroboron bridges, resulting in sharp changes in color. Thus, this novel compound behaves as a highly selective chromogenic sensor for fluoride...

Journal: :Chemical communications 2013
Luo-Qiang Zhang Shiping Yang Xiaolei Huang Jingsong You Feijie Song

A highly efficient and selective Ru-catalyzed direct C2-olefination of indoles, pyrroles, and carbazoles assisted by a removable N-dimethylcarbamoyl group has been developed by using O2 as the terminal oxidant. Both electron-deficient and unactivated alkenes are applicable to the protocol.

Journal: :Chemical communications 2016
Maciej Krzeszewski Paweł Swider Łukasz Dobrzycki Michał K Cyrański Witold Danikiewicz Daniel T Gryko

The presence of steric hindrance triggers different reaction pathways in the intramolecular oxidative aromatic coupling of tetraaryl-pyrrolo[3,2-b]pyrroles and leads to the formation of a fluorene moiety and a new cationic π-system linked together by a spiro carbon atom. Computational studies elegantly rationalized these results. These previously unknown functional dyes emit red light with reas...

Journal: :Molecules 2014
Jairo Quiroga Jaime Gálvez Rodrigo Abonia Braulio Insuasty Alejandro Ortíz Justo Cobo Manuel Nogueras

Diastereoselective reactions between 4-formylpyrazoles, N-substituted maleimides and glycine derivates led to new series of pyrazolyldipyrrolo [3,4-a:3',4'-f]pyrrolizines and pyrazolylpyrrolo[3,4-c]pyrroles in good yields. The reactions proceeded by a domino process through azomethine ylides formed in situ via a 1,3-dipolar cycloaddition reaction.

Journal: :Organic & biomolecular chemistry 2014
Satyasheel Sharma Sangil Han Mirim Kim Neeraj Kumar Mishra Jihye Park Youngmi Shin Jimin Ha Jong Hwan Kwak Young Hoon Jung In Su Kim

The rhodium-catalyzed oxidative C2-olefination of indoles and pyrroles containing N-arylcarboxamide directing groups with a range of alkenes and subsequent cleavage of directing groups is described. This method provides direct and efficient access to C2-functionalized free (NH)-heterocycles.

Journal: :Molecules 2010
Mykhaylo V Vovk Oleksandr M Pinchuk Andrij O Tolmachov Andrei A Gakh

The title compounds, (4-trifluoromethoxyphenyl)-2,5-dimethyl-3-(2-R-thiazol-4-yl)-1H-pyrroles, were prepared in four steps starting from commercially available 4-trifluoromethoxyaniline. The pyrrole (second ring) was added in one step using the Paal-Knorr method. The thiazole (third ring) was added in three steps using chloroacylation with chloroacetonitrile followed by heterocyclization with t...

Journal: :The Journal of organic chemistry 2008
Christophe Blaszykowski Evangelos Aktoudianakis Dino Alberico Cyril Bressy David G Hulcoop Farnaz Jafarpour Arash Joushaghani Benoît Laleu Mark Lautens

A norbornene-mediated palladium-catalyzed sequence is described in which an alkyl-aryl bond and an aryl-heteroaryl bond are formed in one reaction vessel. The aryl-heteroaryl bond-forming step occurs via a direct arylation reaction. A number of six-, seven-, and eight-membered ring-annulated indoles, pyrroles, pyrazoles, and azaindoles were synthesized from the corresponding bromoalkyl azole an...

Journal: :Chemical communications 2014
Yun-He Xu Tao He Qiu-Chi Zhang Teck-Peng Loh

A cyclization reaction between enamides and alkynes catalyzed by palladium(II) acetate is described. In this method, the molecular oxygen serves as an efficient oxidant for the Pd(II)/Pd(0) catalytic cycle. The simple reaction conditions permit this methodology to be used as a general tool for the preparation of multi-substituted pyrroles.

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید