An enantiomerically pure siderophore type ligand for the diastereoselective 1 : 1 complexation of lanthanide(III) ions

• Markus Albrecht,
• Olga Osetska,
• Thomas Abel,
• Gebhard Haberhauer and
• Eva Ziegler

Beilstein J. Org. Chem. 2009, 5, No. 78, doi:10.3762/bjoc.5.78

• ligand leading to a significant change of the observed CD spectra. Small trivalent metal ions like aluminium(III), gallium(III) or iron(III) which are able to form (distorted) octahedral coordination compounds lead to UV–vis spectra which show isosbestic behaviour. However, the titration curves show more

An expedient and new synthesis of pyrrolo[1,2-b]pyridazine derivatives

• Rajeshwar Reddy Sagyam,
• Ravinder Buchikonda,
• Jaya Prakash Pitta,
• Himabindu Vurimidi,
• Pratap Reddy Padi and
• Mahesh Reddy Ghanta

Beilstein J. Org. Chem. 2009, 5, No. 66, doi:10.3762/bjoc.5.66

• removal was accomplished by a Buchi rotary evaporator at house vacuum (30–40 Torr). Solvents and reagents were used without further purification. The purity of compounds was checked on silica gel coated aluminium plates (Merck). (a) Procedure for compound 3: A mixture of 2-[2-(4-fluorophenyl)-2-oxo-1

Coaxial electrospinning of liquid crystal-containing poly(vinylpyrrolidone) microfibres

• Eva Enz,
• Ute Baumeister and
• Jan Lagerwall

Beilstein J. Org. Chem. 2009, 5, No. 58, doi:10.3762/bjoc.5.58

• setup for electrospinning consists of three main components: a chargeable spinneret (e.g. a metallic needle) through which a polymer solution or melt is pumped, a grounded collector (e.g. an aluminium foil) and a high voltage power supply connecting spinneret and collector (see Figure 1). The mechanism

• orientation of the liquid crystal molecules (and the layers of the SmA phase) inside the fibres, 2D X-ray diffraction patterns were recorded. For this purpose two samples of uniformly aligned fibres with maximum LC content were spun between bars of aluminium foil and were then rolled up in two perpendicular

• the fibres were mechanically stable. Oriented fibres for X-ray investigations were spun across parallel bars of aluminium foil placed on the collector. Calorimetry investigations were carried out on a Perkin Elmer Pyris 1 DSC at a heating rate of 10 K min−1. Samples of about 5 to 15 mg fibres were

A convenient method for preparing rigid-core ionic liquid crystals

• Julien Fouchet,
• Laurent Douce,
• Benoît Heinrich,
• Richard Welter and
• Alain Louati

Beilstein J. Org. Chem. 2009, 5, No. 51, doi:10.3762/bjoc.5.51

• . Chromatography was carried out with Merck silica gel 60 (40–63 mm). Analytical TLC was performed with Merck silica gel 60 F254 aluminium sheets. 1H NMR and 13C NMR (300 MHz and 75 MHz respectively) spectra were recorded with a Bruker Avance 300 spectrometer at 25 °C. Chemical shifts, δ, are reported in ppm using

On the functionalization of benzo[e][2,1]thiazine

• Kirill Popov,
• Tatyana Volovnenko and
• Julian Volovenko

Beilstein J. Org. Chem. 2009, 5, No. 42, doi:10.3762/bjoc.5.42

• atom in compounds 5 is much more reactive than the chlorines in 4. Thus, when 5a,b were heated with 2-mercaptoethanol and triethylamine in dioxane, compounds 6a,b were obtained as the sole products (Scheme 1). Amines 7a,b were synthesized by reduction of chloronitriles 2a,b with lithium aluminium

• , 55–57%). General procedure for the synthesis of compounds 7 To a magnetically stirred suspension of 2a,b (1 g, 4 mmol) in dry ether (3 mL) or dry THF (3 mL) lithium aluminium hydride (0.7 g, 16 mmol) was added in small portions at 0 °C. The solution was stirred for 3 hours and the temperature

Mitomycins syntheses: a recent update

• Jean-Christophe Andrez

Beilstein J. Org. Chem. 2009, 5, No. 33, doi:10.3762/bjoc.5.33

• successful approach involved deprotection of the benzyl ether to generate the corresponding phenol 219 followed by reduction of the ester with lithium aluminium hydride and direct oxidation of the phenol to the quinone 221 with molecular oxygen and a catalytic amount of salcomine in an overall 30% yield over

From discovery to production: Scale- out of continuous flow meso reactors

• Peter Styring and
• Ana I. R. Parracho

Beilstein J. Org. Chem. 2009, 5, No. 29, doi:10.3762/bjoc.5.29

• valves for the introduction of inert or reactive gases and a septa for the introduction of reagents. The 12 reaction tubes sit in two stacked aluminium blocks; the lower fits on a hotplate-stirrer and can be maintained at a constant temperature, while the upper block has circulating water which cools the

Enantiospecific synthesis of [2.2]paracyclophane- 4-thiol and derivatives

• Gareth J. Rowlands and
• Richard J. Seacome

Beilstein J. Org. Chem. 2009, 5, No. 9, doi:10.3762/bjoc.5.9

• . Dioxane was stored over sodium wire and DMF was stored over 4Å molecular sieves. (±)-4-Bromo[2.2]paracyclophane (3) All stages of this reaction were performed in the dark by covering the flasks with aluminium foil. Bromine (7.8 mL, 0.15 mol, 1.05 equiv) was dissolved in DCM (1.5 L). 10% of the solution

New diarylmethanofullerene derivatives and their properties for organic thin- film solar cells

• Daisuke Sukeguchi,
• Surya Prakash Singh,
• Mamidi Ramesh Reddy,
• Hideyuki Yoshiyama,
• Rakesh A. Afre,
• Yasuhiko Hayashi,
• Hiroki Inukai,
• Tetsuo Soga,
• Shuichi Nakamura,
• Norio Shibata and
• Takeshi Toru

Beilstein J. Org. Chem. 2009, 5, No. 7, doi:10.3762/bjoc.5.7

• cells. Experimental Representative procedure: Preparation of 1a Methyl 4-[3,4-bis(octyloxy)benzoyl]benzoate (15a) To a solution of terephthalic acid monomethyl ester chloride (3, 268 mg, 1.35 mmol) in CH2Cl2 (6 mL) was added aluminium trichloride (199 mg, 1.49 mmol) in portions at 0 °C and subsequently

Synthesis and redox behavior of new ferrocene- π-extended- dithiafulvalenes: An approach for anticipated organic conductors

• Abdelwareth A. O. Sarhan,
• Omar F. Mohammed and
• Taeko Izumi

Beilstein J. Org. Chem. 2009, 5, No. 6, doi:10.3762/bjoc.5.6

• of 1,1′-bis(2-furoyl)ferrocene (5d). In a dried three-necked flask, a mixture of ferrocene (3.72 g, 0.02 mol) and 2-furoyl chloride (0.02 mol) was stirred in dry CH2Cl2 (100 ml) at 0 °C for 10 min. Anhydrous aluminium chloride (2.8 g, 0.021 mol) was added at such a rate that the reaction mixture

The first direct synthesis of β-unsubstituted meso- decamethylcalix[5]pyrrole

• Luis Chacón-García,
• Lizbeth Chávez,
• Denisse R. Cacho and
• Josue Altamirano-Hernández

Beilstein J. Org. Chem. 2009, 5, No. 2, doi:10.3762/bjoc.5.2

• catalyzed by a Brønsted-Lowry acid such as HCl or methanesulfonic acid, or a Lewis acid such as zeolites with aluminium or cobalt, BF3 or a bismuth salt [2][3][4][5]. The synthesis of calix[n]pyrroles where n > 4 has been reported for n = 5 or 6. The latter compounds have been synthesized via two routes: a

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

• . Samples were introduced by push rod aluminium crucibles. Ions were accelerated by 8 kV in EI mode. Benzene was dried over molecular sieve 4 Å for at least 24 h prior to use. All other solvents and chemicals were used without further purification. Melting points were measured on the B-540 (Büchi) and were

Diastereoselective and enantioselective reduction of tetralin- 1,4-dione

• E. Peter Kündig and
• Alvaro Enriquez-Garcia

Beilstein J. Org. Chem. 2008, 4, No. 37, doi:10.3762/bjoc.4.37

• hydride from the same aluminium moiety (Scheme 3). Conversely, lithium tri-sec-butylborohydride (L-selectride) afforded a product enriched with cis-tetralin-1,4-diol (6) (entry 5). The high diastereoselectivity presumably is a consequence of the bulky reducing agent. Following the first reduction and

End game strategies towards the total synthesis of vibsanin E, 3-hydroxyvibsanin E, furanovibsanin A, and 3-O-methylfuranovibsanin A

• Brett D. Schwartz,
• Craig M. Williams and
• Paul V. Bernhardt

Beilstein J. Org. Chem. 2008, 4, No. 34, doi:10.3762/bjoc.4.34

• modification [31] introduced 3-methylcrotonate functionality (i.e. 45), which gave similar yields to that reported for the benzoate and related studies [25][26][27][28][29][30]. For example, treating 23 with lithium aluminium hydride followed by Swern oxidation gave 46 (77% over two steps) which when treated

• lithium aluminium hydride proceded smoothly, however, global oxidation caused significant problems yielding only very low amounts of aldehyde 52, which was not enough to attempt the Wittig reaction with 45 (Scheme 8). In the view of the diasppointing results obtained above (Scheme 8) all attention was

Total synthesis of the indolizidine alkaloid tashiromine

• Stephen P. Marsden and
• Alison D. McElhinney

Beilstein J. Org. Chem. 2008, 4, No. 8, doi:10.1186/1860-5397-4-8

• desired aldehyde to undergo retro-Mannich fragmentation, and so elected to carry out a reductive work-up to the ozonolysis procedure (Scheme 3). The desired alcohol 8 was obtained in a crude form and immediately subjected to reduction with lithium aluminium hydride to give our target tashiromine 1 in 36

Analogues of amphibian alkaloids: total synthesis of (5R,8S,8aS)-(−)-8-methyl- 5-pentyloctahydroindolizine (8-epi-indolizidine 209B) and [(1S,4R,9aS)-(−)-4-pentyloctahydro- 2H-quinolizin- 1-yl]methanol

• Joseph P. Michael,
• Claudia Accone,
• Charles B. de Koning and
• Christiaan W. van der Westhuyzen

Beilstein J. Org. Chem. 2008, 4, No. 5, doi:10.1186/1860-5397-4-5

• reduced with lithium aluminium hydride in diethyl ether to give the alcohol (−)-23 in 97% yield (See Supporting Information File 1 for full experimental data). The corresponding methanesulfonate (−)-24 (66%) was then defunctionalised by an improved procedure, which entailed treatment with freshly prepared

• behaviour of five- and six-membered enaminones proved to be all too well founded. In the indolizidine series, the robust enaminone 17 survived reduction with lithium aluminium hydride, leaving only the saturated ester to be reduced. With the six-membered analogue 28, the enaminone unit was far more

• synthesis before the introduction of other incompatible functional groups (lactam, thiolactam, enaminone). The only feasible option was to go back to the chiral amine (+)-14, reduction of which with lithium aluminium hydride gave the unstable amino alcohol (+)-30 in 97% yield as long as the amine was added

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

• generation of aluminium waste that needs to be disposed of. Additionally, formation of unidentified side products is very common in this reaction. Therefore, the use of this method especially in large scale preparation might present major drawbacks. To overcome these difficulties we, therefore, focused on

A convenient allylsilane- N-acyliminium route toward indolizidine and quinolizidine alkaloids

• Roland Remuson

Beilstein J. Org. Chem. 2007, 3, No. 32, doi:10.1186/1860-5397-3-32

• chloride and CeCl3. The mixture was then hydrolysed with 1N HCl to give methylenindolizidinones 5a and 5b in a 4:1 ratio. Reduction of the mixture of lactams 5a and 5b with lithium aluminium hydride gave methylenindolizidines 6a and 6b which were separated by flash chromatography. Osmium tetroxide

• 26b with lithium aluminium hydride afforded a 4:1 mixture of methylenindolizidines 27a and 27b in quantitative yield. These isomers were separated. Palladium-catalysed hydrogenation of 27a was found to be stereoselective, giving a mixture of 28a and (-)-(dendroprimine) 22 in a 3:1 ratio. Using similar

• :20). Flash column chromatography gave pure 31a in 18% yield, but 29a and 30a could not be separated (50% yield). A mixture of the three isomers was used without purification for the next step. This mixture was then reduced with lithium aluminium hydride to give the indolizidines 28a, 22 and 29b. In