Facile synthesis of benzothiadiazine 1,1-dioxides, a precursor of RSV inhibitors, by tandem amidation/intramolecular aza-Wittig reaction

• Krishna C. Majumdar and
• Sintu Ganai

Beilstein J. Org. Chem. 2013, 9, 503–509, doi:10.3762/bjoc.9.54

• -boiling-point solvent, i.e., o-dichlorobenzene (DCB). The reaction was successful at higher temperature, affording the desired cyclized product 13b (54%) along with the by-product triphenylphosphine oxide (Table 1, entry 5). Subsequently, we turned our attention to develop a simpler one-step procedure by

A new synthetic protocol for coumarin amino acid

• Xinyi Xu,
• Xiaosong Hu and
• Jiangyun Wang

Beilstein J. Org. Chem. 2013, 9, 254–259, doi:10.3762/bjoc.9.30

• –Wadsworth–Emmons reaction has a significant advantage: The resulting phosphate byproduct can be readily separated, whereas the byproduct triphenylphosphine oxide generated in the Wittig reaction is difficult to remove [17]. The effect of the base used in the Horner–Wadsworth–Emmons reaction on the reaction

Binding of group 15 and group 16 oxides by a concave host containing an isophthalamide unit

• Jens Eckelmann,
• Vittorio Saggiomo,
• Svenja Fischmann and
• Ulrich Lüning

Beilstein J. Org. Chem. 2012, 8, 11–17, doi:10.3762/bjoc.8.2

• sulfoxides were chosen as guests, namely pyridine-N-oxide (PyNO) [18][19] and triphenylphosphine oxide (TPPO). PyNO showed the same behaviour as DMSO, i.e., large CIS for concave host 1, and small CIS for the linear compound (Figure 2, PyNO, endo-CH, 0.34 ppm for 1 and 0.14 ppm for 2). In contrast, with TPPO

• and its non-macrocyclic model 2. Expansion of a part of the 1H NMR spectra (200 MHz, 298 K) of pure 1 and 2 in CD2Cl2 (bottom) and after addition of TBACl, DMSO, pyridine-N-oxide (PyNO), triphenylphosphine oxide (TPPO), from bottom to top, respectively. NH proton (red circles), endo-CH proton (red

The application of a monolithic triphenylphosphine reagent for conducting Appel reactions in flow microreactors

• Kimberley A. Roper,
• Heiko Lange,
• Anastasios Polyzos,
• Malcolm B. Berry,
• Ian R. Baxendale and
• Steven V. Ley

Beilstein J. Org. Chem. 2011, 7, 1648–1655, doi:10.3762/bjoc.7.194

• [34]. This was utilised by Appel in the mid 70s, who reported on the use of triphenylphosphine and carbon tetrachloride to convert an alcohol into the corresponding alkyl chloride [35]. The reaction produces byproducts, such as triphenylphosphine oxide, during the reaction that can be very difficult

• reduced pressure at the end of the reaction along with the solvent. The oxy-phosphonium salt 4 then reacts with the bromide counterion to produce the substituted product 6 along with the triphenylphosphine oxide byproduct (7). However, 3 is in equilibrium with the inverted ion pair 8, which can proceed

• suggests that a complex mixture of phosphorus species is present within the monolith. Triphenylphosphine oxide, from the starting material, and unreacted triphenylphosphine, due to inaccessible sites within the monolith, are probably present along with potentially a complex combination of active

Kinetics and mechanism of vanadium catalysed asymmetric cyanohydrin synthesis in propylene carbonate

• Michael North and
• Marta Omedes-Pujol

Beilstein J. Org. Chem. 2010, 6, 1043–1055, doi:10.3762/bjoc.6.119

• largely be located on silicon as shown in Figure 8a. This was found to be the case (ρ = +0.4) for asymmetric cyanohydrin synthesis catalysed by bimetallic aluminium(salen) complex 6 in the presence of triphenylphosphine oxide [83][84], indicating that most of the catalysis in this case was due to

• activation of the TMSCN by the triphenylphosphine oxide rather than activation of the aldehyde by the metal(salen) complex. In contrast, reactions catalysed by complex 1 gave a Hammett plot with a reaction constant of +2.4, indicating that there was a significant increase in negative charge at the benzylic

• significantly (from +1.6 to +0.4) when the solvent is changed from dichloromethane to propylene carbonate. The results obtained in propylene carbonate are almost identical to those previously obtained with complex 6 and triphenylphosphine oxide as catalyst [52], and are entirely consistent with a significant

A facile synthesis and fungicidal activities of 2-(alkylamino)-5,6-dimethylthieno[2,3-d]pyrimidin- 4(3H)-ones

• Yang-Gen Hu,
• Ai-Hua Zheng,
• Xu-Zhi Ruan and
• Ming-Wu Ding

Beilstein J. Org. Chem. 2008, 4, No. 49, doi:10.3762/bjoc.4.49

• isocyanate (2 mmol) under nitrogen at room temperature. After the reaction mixture was stirred for 6–12 h at 0–5 °C, the solvent was removed under reduced pressure and ether/petroleum ether (1:2, 20 mL) was added to precipitate triphenylphosphine oxide. After filtration, the solvent was removed to give