Synthesis and Optoelectronic Properties of Hexahydroxylated 10‐
<i>O</i>
‐R‐Substituted Anthracenes via a New Modification of the Friedel–Crafts Reaction Using O‐Protected
<i>ortho</i>
‐Acetal Diarylmethanols
作者:Agnieszka Bodzioch、Bernard Marciniak、Ewa Różycka‐Sokołowska、Jeremiasz K. Jeszka、Paweł Uznański、Sylwester Kania、Janusz Kuliński、Piotr Bałczewski
DOI:10.1002/chem.201101909
日期:2012.4.16
new modification of the Friedel–Crafts type intramolecular cyclization involving O‐protected ortho‐acetal diarylmethanols as a new type of reactant, was carried out for the first time in a medium containing a large amount of water at room temperature and enabled synthesis of a series of electron‐rich, hexahydroxylated 10‐O‐R‐substituted anthracenes, where R is an alkyl (Me, nBu, n‐C16H33) or arylalkyl
室温下首次在含有大量水的介质中进行了Friedel-Crafts型分子内环化的新修饰,涉及O保护的邻缩醛二芳基甲醇作为新型反应物。系列富电子,hexahydroxylated 10- ö -R-取代的蒽,其中R是烷基(Me中,ñ卜,ñ -C 16 ħ 33)或芳烷基(CH 2 PH,CH 2 -2- Napht,CH 2 C 6 H 4 CH 2OAr),并评估它们在溶液,晶体和固体薄膜中的电子和光电性能。在此转化过程中,形成了一个中心10 - O -R-取代的苯环,该环稠合到源自两个独立芳族醛的环上。该反应通过两种已鉴定的涉及缩醛和/或游离醛基的机理进行。对酸敏感的乙缩醛和二苄基烷氧基官能团从未在分子内Friedel-Crafts型环化反应中一起使用。新化合物显示出深蓝色荧光,溶液中的量子产率约为0.3。通过在玻璃上真空沉积获得的薄膜所研究的电学特性取决于10 - O -R-取代基,并且在10
Ultrasound-assisted synthesis of RO- and RS-substituted (hetero)acenes via oxo- and thio-Friedel-Crafts/Bradsher reactions
o-dithioacetalaryl(aryl)methyl thioethers underwent ultrasound-assisted cyclization in nonaqueous medium (FeCl3/KI/EtOH) in less than 25 min., in lower yields than in the "oxygen variant" to give RS-substituted (hetero)acenes. The RO-(hetero)acenes cyclized at 25-60 °C in aqueous media but did not cyclize in organic solvents while the RS-(hetero)acenes required higher temperatures 55-60 °C and cyclized in
A Synthetic Route to Highly Substituted 1,2,3,4-Tetrahydroisoquinolines via Yb(OTf)3-Catalyzed Diastereoselective Ring Opening of Bridged Oxazolidines: Asymmetric Synthesis of 2-Azapodophyllotoxin
作者:Ajay Kumar Srivastava、Minseob Koh、Seung Bum Park
DOI:10.1002/chem.201002938
日期:2011.4.18
aldehydes and transformed into fully functionalized THIQs viadiastereoselectiveringopening with various nucleophiles in the presence of Yb(OTf)3. This methodology furnished four out of eight possible diastereomers of 1,2,3,4‐tetrasubstituted THIQs despite the electronic nature of substituents on the aryl rings. Finally, the enantioselective synthesis of 2‐azapodophyllotoxin was achieved with an overall