Continuous-flow hydration–condensation reaction: Synthesis of α,β-unsaturated ketones from alkynes and aldehydes by using a heterogeneous solid acid catalyst

• Magnus Rueping,
• Teerawut Bootwicha,
• Hannah Baars and
• Erli Sugiono

Beilstein J. Org. Chem. 2011, 7, 1680–1687, doi:10.3762/bjoc.7.198

• drop in chemical yield was observed when the flow rate increased from 0.5 mL min−1 to 1.0 mL min−1 (Table 1, entry 2 versus entry 8), indicating that the flow rate should be 0.5 mL min−1. Further reaction optimization was accomplished by varying the substrate concentration. While the chemical yields

Gold(I)-catalyzed synthesis of γ-vinylbutyrolactones by intramolecular oxaallylic alkylation with alcohols

• Michel Chiarucci,
• Mirko Locritani,
• Gianpiero Cera and
• Marco Bandini

Beilstein J. Org. Chem. 2011, 7, 1198–1204, doi:10.3762/bjoc.7.139

• the present gold-catalyzed oxaallylic alkylation reaction. Gold-catalyzed synthesis of γ-lactones 4 from the corresponding monoesters 3. Mechanistic sketch of the gold-promoted oxaallylic alkylation reaction. Optimization of the reaction conditions for the lactonization of 1a.a Proving the scope of

The Eschenmoser coupling reaction under continuous-flow conditions

• Sukhdeep Singh,
• J. Michael Köhler,
• Andreas Schober and
• G. Alexander Groß

Beilstein J. Org. Chem. 2011, 7, 1164–1172, doi:10.3762/bjoc.7.135

• minimum residence time. For small scale synthesis flow chemistry is of great advantage to realize these conditions on the laboratory bench safely [18]. Results and Discussion For the reaction optimization we have focused on a straightforward procedure that finally prevents the isolation of the S-alkylated

Evaluation of a commercial packed bed flow hydrogenator for reaction screening, optimization, and synthesis

• Marian C. Bryan,
• David Wernick,
• Christopher D. Hein,
• James V. Petersen,
• John W. Eschelbach and
• Elizabeth M. Doherty

Beilstein J. Org. Chem. 2011, 7, 1141–1149, doi:10.3762/bjoc.7.132

• run-to-run reproducibility of the H-Cube® reactor for screening and reaction optimization is discussed. Keywords: catalyst leaching; CatCart®; H-Cube®; packed bed flow hydrogenation; Introduction The potential advantages of heterogeneous catalytic flow hydrogenation over traditional batch reactor

Unusual behavior in the reactivity of 5-substituted-1H-tetrazoles in a resistively heated microreactor

• Bernhard Gutmann,
• Toma N. Glasnov,
• Tahseen Razzaq,
• Walter Goessler,
• Dominique M. Roberge and
• C. Oliver Kappe

Beilstein J. Org. Chem. 2011, 7, 503–517, doi:10.3762/bjoc.7.59

• continuous flow processes is becoming increasingly important. In the past few years our research group [19][20][21][22][23][24][25] has reported a number of successful case studies where initial reaction optimization for a variety of synthetic transformations was performed under batch microwave conditions

Expedient syntheses of the N-heterocyclic carbene precursor imidazolium salts IPr·HCl, IMes·HCl and IXy·HCl

• Lukas Hintermann

Beilstein J. Org. Chem. 2007, 3, No. 22, doi:10.1186/1860-5397-3-22

• source of the chloride counter ion. The choice fell on chlorotrimethylsilane (TMSCl), the "silyl version" of HCl, which is easily measured and handled. The current pricing of TMSCl is 8 €/mol, as opposed to 80–100 €/mol for HCl/dioxane (4 M). The reaction optimization went as follows: Initial experiments