نتایج جستجو برای: friedländer hetero annulation

تعداد نتایج: 5992  

2013
Aleksey I Gerasyuto Zhi-Xiong Ma Grant S Buchanan Richard P Hsung

A successful enone version of an intramolecular aza-[3 + 3] annulation reaction is described here. Use of piperidinium trifluoroacetate salt as the catalyst and toluene as the solvent appears to be critical for a successful annulation. We also demonstrated for the first time that microwave irradiation can accelerate aza-[3 + 3] annulation reactions. An attempt to expand the scope of the enone a...

2015
Sebastian Resch Thomas Quell Dieter Schollmeyer Siegfried R. Waldvogel

The hetero-tetra-cene skeleton of the title mol-ecule, C23H14Br2N2OS, is defined by linear annulation of four six-membered rings, including two N heteroatoms. This moiety is nearly planar (r.m.s. deviation = 0.055 Å), with a slight twist of 4.1 (2)° between the two halves of the aromatic system. The dihedral angle between the least-squares plane of the skeleton and the benzyl group is 24.5 (3)°...

2016
Bo Zhu Shuai Qiu Jiangtao Li Michelle L. Coote Richmond Lee Zhiyong Jiang

Versatile synthetic strategies that access diverse chemical substrates in a highly chemoand stereoselective manner are crucial but demanding. Construction of chiral molecules with multiple (hetero)quaternary carbon stereocenters in a single fashion is a particularly significant challenge, with important applications in the synthesis of a range of bioactive compounds containing the 1,4-sulfur br...

Journal: :Organic & biomolecular chemistry 2006
Matej Babjak Alice Kanazawa Regan J Anderson Andrew E Greene

A short, efficient synthesis of 22-hydroxyacuminatine, starting from a readily accessible hydroxy pyridone, is presented; key steps include a Heck coupling with methyl pentadienoate, a flash vacuum pyrolytic cyclization, and a Friedländer condensation.

Journal: :Chemical communications 2015
Sébastien Dhers Jean-Pierre Costes Philippe Guionneau Carley Paulsen Laure Vendier Jean-Pascal Sutter

Rare cases of genuine (i.e. field-free) SMM have been found for mixed 3d-4f-5d ring-shaped compounds with Tb(III) (Ueff/kB = 23.0 K) or Dy(III) (Ueff/kB = 26.4 K). The ferromagnetic interactions between the transition metals are shown to play an essential role in this feature.

Journal: :DMW - Deutsche Medizinische Wochenschrift 1887

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