Thermodynamic and kinetic stabilization of divanadate in the monovanadate/divanadate equilibrium using a Zn-cyclene derivative: Towards a simple ATP synthase model

• Hanno Sell,
• Anika Gehl,
• Frank D. Sönnichsen and
• Rainer Herges

Beilstein J. Org. Chem. 2012, 8, 81–89, doi:10.3762/bjoc.8.8

• condensation, e.g., the formation of ATP [8]. A large number of thoroughly investigated enzymes hydrolyze phosphates and provide insight into conceivable mechanisms of phosphate or vanadate condensations. In phosphatases, kinases and ATP synthase, the catalyzed transfer of phosphate usually requires the

• artificial system driving endergonic condensations (Figure 1), we draw the conclusion that only one of the binding sites should provide metal coordination to the vanadate (or phosphate) and the other binding site should associate the nucleophilic anion by neutral hydrogen bonds. Similar effects obviously

Ugi post-condensation copper-triggered oxidative cascade towards pyrazoles

• Aurélie Dos Santos,
• Laurent El Kaim,
• Laurence Grimaud and
• Caroline Ronsseray

Beilstein J. Org. Chem. 2011, 7, 1310–1314, doi:10.3762/bjoc.7.153

• ; isocyanide; pyrazolidinone; Introduction In the last twenty years, the Ugi reaction coupled with its various post-condensations towards heterocyclic libraries has established the success of isocyanide-based multicomponent reactions [1][2][3][4][5][6][7]. Chemists in both academia and industry have taken

• cascade. Among potential Ugi post-condensations, radical and oxidative processes represent a very promising route towards the formation of complex scaffolds. We are currently exploring the reactivity of the N-aryl Ugi–Smiles adducts using similar strategies. Experimental Typical procedure for the first

Construction of cyclic enones via gold-catalyzed oxygen transfer reactions

• Leping Liu,
• Bo Xu and
• Gerald B. Hammond

Beilstein J. Org. Chem. 2011, 7, 606–614, doi:10.3762/bjoc.7.71

• conjugated enone substructure has attracted the interest of synthetic chemists for decades. Among numerous methodologies, aldol condensations and Wittig-type reactions have been widely utilized [9][10][11][12][13][14][15][16][17][18]. Recently, it was found that conjugated enones could be generated from the

An overview of the key routes to the best selling 5-membered ring heterocyclic pharmaceuticals

• Marcus Baumann,
• Ian R. Baxendale,
• Steven V. Ley and
• Nikzad Nikbin

Beilstein J. Org. Chem. 2011, 7, 442–495, doi:10.3762/bjoc.7.57

An efficient and practical entry to 2-amido-dienes and 3-amido-trienes from allenamides through stereoselective 1,3-hydrogen shifts

• Ryuji Hayashi,
• John B. Feltenberger,
• Andrew G. Lohse,
• Mary C. Walton and
• Richard P. Hsung

Beilstein J. Org. Chem. 2011, 7, 410–420, doi:10.3762/bjoc.7.53

• -dienes see [51][52]). Problems with the two primary approaches to access amido-dienes [47] are that acid-mediated condensations suffer from functional group tolerances, and metal-mediated coupling methods (for reviews on Cu-mediated C–N and C–O bond formations see [53][54][55], for some examples see [56

Molecular rearrangements of superelectrophiles

• Douglas A. Klumpp

Beilstein J. Org. Chem. 2011, 7, 346–363, doi:10.3762/bjoc.7.45

• . Condensations of ninhydrin (28) with benzene. Rearrangement of 29 to 30. Superacid promoted ring opening of succinic anhydride (33). Reaction of phthalic acid (36) in FSO3H-SbF5. Ring expansion of superelectrophile 42. Reaction of camphor (44) in superacid. Isomerization of 2-cyclohexen-1-one (48

Reciprocal polyhedra and the Euler relationship: cage hydrocarbons, C_nH_n and closo-boranes [B_xH_x]²⁻

• Michael J. McGlinchey and
• Henning Hopf

Beilstein J. Org. Chem. 2011, 7, 222–233, doi:10.3762/bjoc.7.30

• prerequisite for an intramolecular [2 + 2] photoaddition had been created. Indeed, photochemical ring closure and various oxidation steps led to the "open" triketone 70 that in principle should be convertible to a seco-decahedrane skeleton by two aldol condensations. This latter system should close to 14 by

Hydroxyapatite supported caesium carbonate as a new recyclable solid base catalyst for the Knoevenagel condensation in water

• Monika Gupta,
• Rajive Gupta and
• Medha Anand

Beilstein J. Org. Chem. 2009, 5, No. 68, doi:10.3762/bjoc.5.68

• , respectively. There is no data with respect to the rate of condensation versus dehydration or 1,2-elimination of the product. In all cases, no doubt, the yields were appreciable, but involved tedious separation. Electrochemically induced Knoevenagel condensations [38] have been reported but require solvents

Asymmetric synthesis of biaryl atropisomers by dynamic resolution on condensation of biaryl aldehydes with (−)-ephedrine or a proline- derived diamine

• Ann Bracegirdle,
• Jonathan Clayden and
• Lai Wah Lai

Beilstein J. Org. Chem. 2008, 4, No. 47, doi:10.3762/bjoc.4.47

• benzene-d6 in an NMR tube (Scheme 2). The temperature of the tube was raised stepwise from rt to 110 °C as indicated in Table 2, allowing 30 min at each temperature and monitoring the changing ratio of diastereoisomers by 1H NMR. We assume that the condensations are diastereoselective at the new

An improved synthesis of 1,3,5-triaryl- 2-pyrazolines in acetic acid aqueous solution under ultrasound irradiation

• Ji-Tai Li,
• Xiao-Hui Zhang and
• Zhi-Ping Lin

Beilstein J. Org. Chem. 2007, 3, No. 13, doi:10.1186/1860-5397-3-13

• Table 2. The following sequence of reaction appears to afford a satisfactory explanation of the mode of formation of the products (Scheme 2). This reaction involves the initial formation of an arylhydrazone with subsequent attack of nitrogen upon the carbon-carbon double bond. Condensations involving