Novel loop-like aromatic compounds: a further step on the road to nanobelts and nanotubes

• Venkataramana Rajuri,
• Dariush Ajami,
• Gaston R. Schaller,
• Christian Näther and
• Rainer Herges

Beilstein J. Org. Chem. 2010, 6, No. 30, doi:10.3762/bjoc.6.30

• reaction [7][8][11] and ring enlargement metathesis [12][13][14][15] of 9,9′,10,10′-tetradehydrodianthracene (TDDA) (7) [16]. In a second step we anticipated closing the tube walls by cyclodehydrogenation [17]. Results and Discussion We now report on the synthesis of five new compounds, two hydrocarbons

• analysis. The pure hydrocarbons 2 and 3 were prepared by Diels–Alder reaction of either 7 or 1 [20] with 1,2-bis(dibromomethyl)benzene (8) and sodium iodide to furnish the desired compounds, 2 and 3, in 60 and 40% yield, respectively (Scheme 1 and Scheme 2). During this simple one pot reaction, the sodium

• aromatic hydrocarbons form 1:1-complexes with silver(I). In all-Z-tribenzo[12]annulene [23], for instance, the Ag+ ion is coordinated by three double bonds in a crown-like geometry. Even although three double bonds with a similar geometry are available in our [12]annulene 2, coordination of the Ag+ ion is

Acid- mediated reactions under microfluidic conditions: A new strategy for practical synthesis of biofunctional natural products

• Katsunori Tanaka and
• Koichi Fukase

Beilstein J. Org. Chem. 2009, 5, No. 40, doi:10.3762/bjoc.5.40

• products or the alkyl group-migrated compounds were produced. As expected, these hydrocarbons were very difficult to separate from the desired diene 20, even by repeated distillation or by silica gel chromatography, although the latter is not realistic for kilogram-scale purification. Inspired by the

Chemoselective reduction of aldehydes by ruthenium trichloride and resin- bound formates

• Basudeb Basu,
• Bablee Mandal,
• Sajal Das,
• Pralay Das and
• Ashis K. Nanda

Beilstein J. Org. Chem. 2008, 4, No. 53, doi:10.3762/bjoc.4.53

• as hydrocarbons [4], primary and secondary alcohols [5][6], and formic acid and its salts [7][8][9][10][11] have been used as the hydrogen source. Besides the use of Rh, Ir, Ni and Pd metals in CTH, carbonyl reduction using the combination of Ru(II)-ligand complexes and propan-2-ol in the presence of

Synthesis of 2,3,6,7-tetrabromoanthracene

• Christian Schäfer,
• Friederike Herrmann and
• Jochen Mattay

Beilstein J. Org. Chem. 2008, 4, No. 41, doi:10.3762/bjoc.4.41

• , such as 2,3,6,7-tetradehydroanthracene (for constructing polycyclic aromatic hydrocarbons [13][14]) and 2,6,9,10-tetracyanoanthracene (which has been used as sensitizer for organic photoconductors [15]). Results and Discussion In Scheme 1, the reaction pathway is shown, starting from benzene, which is

Shape- persistent macrocycle with intraannular alkyl groups: some structural limits of discotic liquid crystals with an inverted structure

• Sigurd Höger,
• Jill Weber,
• Andreas Leppert and
• Volker Enkelmann

Beilstein J. Org. Chem. 2008, 4, No. 1, doi:10.1186/1860-5397-4-1

• ). The repeated purification process for all macrocycles was not optimized and is responsible for the rather low yield in the cyclization step. Our recent progress in the synthesis of functionalized polycyclic aromatic hydrocarbons (PAHs) opened the question about the influence of the presence of PAH

Part 1. Reduction of S-alkyl- thionocarbonates and related compounds in the presence of trialkylboranes/air

• Jean Boivin and
• Van Tai Nguyen

Beilstein J. Org. Chem. 2007, 3, No. 45, doi:10.1186/1860-5397-3-45

• reduction of S-alkyl-thionocarbonates, iodides and related compounds to the corresponding hydrocarbons at room temperature with good to excellent yields is described. This method uses a trialkylborane in excess (Et3B or Bu3B) and air. Background The reduction of functional groups such as S-alkyl

• similar compounds to the corresponding hydrocarbons that requires a trialkylborane in excess and air as initiator, at 20°C, or even at lower temperature.[17][18] Results and discussion During the last two decades, the number of applications of Et3B as radical initiator has increased tremendously. As Et3B

Transition- metal/Lewis acid free synthesis of acyl benzothiophenes via C-C bond forming reaction

• Sarbani Pal,
• Mohammad Ashrafuddin Khan,
• P. Bindu and
• P. K. Dubey

Beilstein J. Org. Chem. 2007, 3, No. 35, doi:10.1186/1860-5397-3-35

• starting materials and mild reaction conditions, ii) environmentally safe as the protocol is free from the use of inorganic Lewis acids as well as chlorinated hydrocarbons as solvent, iii) simple operational procedure. However, formation of a mixture of regioisomers is the major drawback of this protocol