Synthesis and in silico screening of a library of β-carboline-containing compounds

• Kay M. Brummond,
• John R. Goodell,
• Matthew G. LaPorte,
• Lirong Wang and
• Xiang-Qun Xie

Beilstein J. Org. Chem. 2012, 8, 1048–1058, doi:10.3762/bjoc.8.117

• diastereomers. Low to moderate yields for this two-step reaction sequence were attributed to a problematic tosylation due to the sterically hindered nature of the indole nitrogen atom. Moreover, unforeseen limitations were encountered for the heteroaromatic and naphthyl-containing β-carboline intermediates

Reduction of benzylic alcohols and α-hydroxycarbonyl compounds by hydriodic acid in a biphasic reaction medium

• Michael Dobmeier,
• Josef M. Herrmann,
• Dieter Lenoir and
• Burkhard König

Beilstein J. Org. Chem. 2012, 8, 330–336, doi:10.3762/bjoc.8.36

• activation by adjacent benzylic or carbonyl groups the reaction stops at the corresponding alkyl iodide. A quantitative mass-efficiency analysis [39] of the reaction in comparison to tosylation/LAH, Ti(III)-mediated and Barton–McCombie reduction revealed a better atom economy and mass efficiency

The preparation of 3-substituted-1,5-dibromopentanes as precursors to heteracyclohexanes

• Bryan Ringstrand,
• Martin Oltmanns,
• Jeffrey A. Batt,
• Aleksandra Jankowiak,
• Richard P. Denicola and
• Piotr Kaszynski

Beilstein J. Org. Chem. 2011, 7, 386–393, doi:10.3762/bjoc.7.49

• steps starting from alkylation of malonate diester followed by reduction of the esters, tosylation of the alcohols, carbon homologation with NaCN, hydrolysis of the cyano groups to carboxylic acids, and lastly a second reduction to VII. Overall yields of diols VII using Method 1A are around 10% [27][28

Anion–π interactions influence pK_a values

• Christopher J. Cadman and
• Anna K. Croft

Beilstein J. Org. Chem. 2011, 7, 320–328, doi:10.3762/bjoc.7.42

• indicated that aromatics in close proximity to an incipient carbocation could accelerate tosylation reactions by up to 1800-fold [21]. Similarly, neighbouring aromatics have been shown to have an effect on radical reactions proceeding through a polarised transition state [22]. Clearly there is excellent

Synthesis and crystal structures of multifunctional tosylates as basis for star-shaped poly(2-ethyl-2-oxazoline)s

• Richard Hoogenboom,
• Martin W. M. Fijten,
• Guido Kickelbick and
• Ulrich S. Schubert

Beilstein J. Org. Chem. 2010, 6, 773–783, doi:10.3762/bjoc.6.96

• recrystallization from ethanol. The synthesis of the tetra-tosylate (TetraTos; Scheme 1) and hexa-tosylate (HexaTos; Scheme 1) compounds was based on tosylation of pentaerythritol and dipentaerythritol, respectively, which are both insoluble in dichloromethane. Therefore, the solvent was changed to pyridine, which

• . 1H and 13C NMR spectroscopy and elemental analysis, the chemical structures of the TetraTos and HexaTos were verified by MALDI-TOF MS, revealing only the desired mass peak corresponding to full tosylation (Figure 2). The absence of residual hydroxyl groups is of major importance for the use of these

• the corresponding alcohols with tosyl chloride. The tosylation of (di)pentaerythritols was only successful using pyridine as solvent due to the limited solubility of the respective educts in dichloromethane. Recrystallization of these tosylate compounds yielded single crystals, and the X-ray crystal

Recent progress on the total synthesis of acetogenins from Annonaceae

• Nianguang Li,
• Zhihao Shi,
• Yuping Tang,
• Jianwei Chen and
• Xiang Li

Beilstein J. Org. Chem. 2008, 4, No. 48, doi:10.3762/bjoc.4.48

• alcohol 215. Tosylation and hydrogenolysis with LiEt3BH removed the C-30 OTs group affording the SEM ether 216. The remaining steps for the completion of total synthesis of asiminecin were carried out along the lines described for asiminocin. Total synthesis of (+)-(30S)-bullanin (+)-Bullanin was isolated

• InCl3 in the presence of aldehyde 218a afforded the expected anti-adduct 220. Addition of stannane 222 to aldehyde 221 in the presence of BF3·OEt2 afforded the syn-adduct 223 as the only detectable stereoisomer. Tosylation of the alcohol followed by exposure to TBAF promoted bis-THF cyclization

• employed the (R)-α-OSEM allylic stannane 261 reaction with the dialdehyde 262 obtained from (S,S)-diethyl tartrate to afford the bis-adduct 263 (Scheme 36). Treatment of 263 with TBAF led to the core bis-THF intermediate, diol 264. Mono tosylation and subsequent hydrogenolysis with LiBEt3H gave alcohol 265