作者:Faouzi Aloui、Riadh El Abed、Taha Guerfel、Béchir Ben Hassine
DOI:10.1080/00397910600588934
日期:2006.6.1
Abstract A new disubstituted hexahelicene derivative 3 bearing methoxy functions at positions 3 and 14 has been prepared in racemic form through a Heck reaction followed by photocyclodehydrogenation. Suitable crystals of rac‐3 were analyzed by X‐ray crystallography and showed similar geometry to the structure of hexahelicene itself. Deprotection of 3 using boron tribromide led to 3,14‐dihydroxyhexahelicene
Synthesis and photo-physical properties of methoxy-substituted π-conjugated-2,2′-bipyridines
作者:Tanmay Chatterjee、Monima Sarma、Samar K. Das
DOI:10.1016/j.tetlet.2010.02.027
日期:2010.4
4,4'-Bis-vinly-2,2' bipyridines have been known in the area of materials chemistry since last few decades. Bipyridine molecules bearing donor substituents in their pi backbone are examples of 'push-pull' molecules. Emissive properties of such ligands depend on the position of the donor unit in their pi backbone. The Horner-Wordsworth-Emmons reaction has been used extensively to synthesize such types of conjugated systems. Three newly synthesized highly conjugated 2,2' bipyridines (3a-c) have been described. The molecules 3a-c are highly emissive in the visible region at room temperature. (C) 2010 Elsevier Ltd. All rights reserved.
Stereoselective Peterson Olefinations from Bench-Stable Reagents and<i>N</i>-Phenyl Imines
作者:Manas Das、Atul Manvar、Maïwenn Jacolot、Marco Blangetti、Roderick C. Jones、Donal F. O'Shea
DOI:10.1002/chem.201500475
日期:2015.6.8
The synthesis of bench‐stable α,α‐bis(trimethylsilyl)toluenes and tris(trimethylsilyl)methane is described and their use in stereoselective Peterson olefinations has been achieved with a wide substrate scope. Product stereoselectivity was poor with carbonyl electrophiles (E/Z ∼1:1 to 4:1) though this was significantly improved by employing the corresponding substituted N‐benzylideneaniline (up to 99:1)
Novel Carbazole‐Based<i>N</i>‐Heterocyclic Carbene Ligands to Access Synthetically Relevant Stilbenes in Pd‐Catalyzed Coupling Processes
作者:Tejpalsingh Ramsingh Girase、Anant R. Kapdi
DOI:10.1002/asia.201900419
日期:2019.8
A series of new carbazole‐based N‐heterocyclic carbene (NHC) ligands have been synthesized in a simple and facile synthetic route and subsequently used in a Pd/carbazole‐based NHC catalytic system, which was found to be effective in catalyzing Heck reactions to provide substituted stilbene derivatives in good yields. Several bioactive stilbenes, including pterostilbene, pinosylvin, trimethoxy resveratrol